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THE

VOYAGE OF H.M.S. CHALLENGER.

ZOOLOGY-VOL. XIII.

REPORT

ON THE

SCIENTIFIC RESULTS

OF THE

VOYAGE OF H.M.S. CHALLENGER

DURING THE YEARS i87 3-7 6

UNDER THE COMMAND OF

Captain GEORGE S. NARES, R.N., F.R.S.

AND THE LATE

Captain FRANK TOURLE THOMSON, R.N.

PREPARED UNDER THE SUPERINTENDENCE OF

THE LATE

Sir C. WYVILLE THOMSON, Knt, F.R.S., &c.

REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH
DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD

AND NOW OF

JOHN MURRAY

ONE OF THE NATURALISTS OF THE EXPEDITION

Zoology— Vol. XIII.

Pui)list)eli bp <0rtJer of !^er ifiajestp's (Sobernment

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1885

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CONTENTS.

I. — Report on the Lamellibranchiata collected by H.M.S. Challenger, during the

The Editor of the Challenger Reports will be greatly obliged to
Authors sending him copies of separate papers, or references to
works, in which the Challenger discoveries are referred to, or the
observations of the Expedition are discussed.

This will greatly facilitate the compilation of a complete Biblio-
graphy, and the discussion of the results of the Expedition, in the
final Volume of the Series.

Letters and Papers should be addressed—

JOHN MURRA V,

Challenger Office,

22 Queen Street,

EDINBURGH. "S

jt i,fj'v « vyi-'wt/L^ww M| v'f ^» v/ I, i^ *#cLyc. # J.v^i_»-:i: } vic»^ i/vwi/

X yjKjO'j

CONTENTS.

I. — Report on the Lamellibranchiata collected by H.M.S. Challenger, during the

years 1873-1876.

By Edgar A. Smith, F.Z.S., Assistant in the Zoological Department of the

British Museum.

{Received 22nd Januarij 1885 ; Appendices, 11th and 18th June 1885.)

11. — Report on the Gephyrea collected by H.M.S. Challenger, during the years

1873-1876.

By Dr. Emil Selenka, Professor in the University oi Erlangen.

{Received 12th March 1885.)

III. — Report on the Sghizopoda collected by H.M.S. Challenger, during the years

1873-1876.

By Professor G. 0. Sars, of the University of Christiania,

{First Instalment of Manuscript received 27th November 1884 ; the last 7th July 1885.)

ERBA TA.

PAET XXXV.

Page 9, line 3 from foot, for " longicallis " read " longicallus."

Page 14, line 14 from foot, for " Circe australis, Angas " read " Circe angccsi, n. sp."

Page 14, line 1 from foot, for " Corbula truncata " read " Corbula hinicata."

Page 17, line 4 from foot, for " Ccclodon elongata " read " Gcelodon elongatus."

Page 18, line 4 from foot, for " Solen " read " Solecurtus."

Page 20, line 5 from foot, for " Crytodon luzonica " read " Crytodon luzonicus."

Page 20, line 2 from foot, insert " (Chemnitz) " after " Pecten vitreus."

Page 24, line 8 from foot, for " Crytodon fcdklandica " read " Crytodon falhlandicus"

Page 25, line 4 from foot, for " Leda jeffrcysii" read " Leda jeffreysi."

Page 25, line 3 from top, for ^' Mactra {Trigonella) iscd)elliana " read " Mactra {Trigonella) isabellcana."

Page 121, line 19 from foot, for " Bosina" read " Dosinia."

Page 251, line 4 from foot, delete "n. sp."

Page 282, line 5 from foot, for " meridionalis" read " vieridionalc."

EDITOEIAL NOTES.

This volume contains Parts XXXV., XXXVI., and XXXVII. of the

Zoological Series of Reports on the Scientific Results of the Expedition.

Part XXXV. — On the return of the Expedition the Mollusca were placed
in the hands of the Rev. R. Boog Watson, F.R.S.E., for description; but
after separating out the different species, and labelling the greater part of the
known ones, Mr. Watson determined, on account of the large size of the
collection, to limit his work to the description of the Scaphopoda and
Gasteropoda.

Mr. Edgar A. Smith, F.Z.S., of the British Museum was then requested
to undertake the preparation of the Report on the Lamellibranchiata. This
he consented to do, and this Part gives the result of his investigations.

Mr. Watson's own Report is now nearly all in type, and will be published
in the course of a few months.

Part XXXVI. — The description of the Gephyrea collected by the
Expedition was originally undertaken by Professor E. Ray Lankester, F.R.S.,
but after the publication of Professor Selenka's splendid systematic Monograph
on this group. Professor Lankester suggested that it would be much better
if an arrangement could be made by which Professor Selenka should take
over the examination of the Challenger collection. Professor Selenka com-
plied with a request to do so, and this Part gives the result of his labours.

The Report was translated from the German by J. Arthur Thomson,
Esq., M.A.

viii THE VOYAGE OF H.M.S. CHALLENGEE.

Part XXXVII. — This Part consists of a Report on the Schizopoda of
the Expedition, by the well-known Carcinologist, Professor G. O. Sars, of
Christiania. In addition to the present Report. Professor Sars has under-
taken another on the Cumacea and Phyllocarida, which will be published in
the course of next year.

John Murray.

Challengbk Office, 32 Queen Street,
Edinburgh, Isf October 1885.

THE

VOYAGE OF H.M.S. CHALLENGER.

ZOOLOGY.

REPORT on the Lamellibrancuiata collected by H.M.S. Challenger during
the Years 1873-76. By Edgar A. Smith, F.Z.S., Assistant in the
Zoological Department of the British Museum.

INTRODUCTION.

The following Report upon the Lamellibranchiata obtained during the Challenger
Expedition consists almost exclusively of a list of the vaiious species compiised in the
collection, with such remarks connected with each as were thought to be of sufficient
interest for publication, and of the descriptions of the numerous forms which apparently
are new to science. The time at my disposal for the preparation of the work ha\'ing
been rather limited, the revision of several of the genera, which in the course of studying
some of the species has appeared desirable, has had to be abandoned. Only in a few
instances has an account of the soft parts preserved in spirit been given, as these are to
be placed in other hands for examination and anatomical description.

Before the collection was handed over to me it had already to a great extent been
identified by the Rev. R. Boog Watson, who is reporting on the Scaphopoda and
Gasteropoda of the Expedition, and it is with much pleasure that I bear testimony to
the very great assistance I have derived from his labours.

In the first place, I escaped the great trouble of sorting the numerous species into
separate boxes and bottles, and of writing the localities, depths, &c., upon them. This,
however, is but a slight advantage in comparison with that of having the identifications
of one whose powers of perception are second to those of no other conchologist of my
acquaintance, and whose carefulness and thoroughness must have been recognised by

(ZOOU CHALL. EXP. — PART XXXV. — 1885.) Mm 1

2 THE VOYAGE OF H.M.S. CHALLENGER.

all fellow-workers, whom, in the course of the preparation of his Report, he may have
consulted. This is also a fitting place to record the assistance I have derived from
the late Dr. Gwyu Jcfi'roy's writings on the deep-sea fauna of the North Atlantic, and to
acknowledge his courtesy in kindly giving his opinion upon certain difficult and doubtful
questions. To my friend W. H. Dull, of the Smithsonian Institution, I am under similar
obligations.

The name Pelecypoda given to this section of MoUusca by Goldfuss ' ought, I think,
to be used in preference to that of Lamellibranchiata. Not only has it priority, but, as
pointed out by Stoliczka, it is also more in uniformity with the nomenclature of the other
classes of Mollusca, the Cephalopoda, Pteropoda, Gasteropoda, &c., and points to the
modification of one of the most important organs — that of locomotion — of the animals.

This class was designated Lamellibranches by Blainville ^ as early as the year 1816,
four years before the publication of Pelecypoda by Goldfuss, but was not characterised,
and the term Lamellibranchiata, accomj^auied by a description of the class, did not appear
until the year 1824, in Blainville's article on Mollusca in the Diet. d. Sci. Nat., vol. xxxii.
p. 306. It will therefore be seen that Pelecypoda, although published somewhat later
than Lamellibi'anches, was in reality the first to be characterised. I should also here
notice that Blainville imposed the name Tetrabranches upon the bivalves^ two years
before the invention of Lamellibranches, but, in that instance also, unaccompanied by
any description. The class-names " Acephala" of Cuvier and " Conchifera" of Lamarck
were published a year or two prior to the appearance of Goldfuss's work, but, as they
include groups which are regarded in modern science as distinct classes, their adoption is
not advisable, seeing that Pelecypoda applies only to true bivalve MoUuscs as now under-
stood. The name Lamellibranchiata is used in the present Eeport as it appears in the
several works published by Sir Wyville Thomson, Professor H. N. Moseley, and others in
connection with the voyage of the Challenger, also in the Narrative of the Cruise, and
because it had already been wTitten on some of the plates before this subject of nomen-
clature had been studied.

In describing the new species I have deemed it advisable to give Latin diagnoses, as
practical experience has proved to me the advantage of such descriptions, and the custom
is adopted by continental writers almost without exception. Through long use the Latin
terminology has acquired a settled signification, and is generally understood, which is not
the case in resj)ect of other languages, and the time has not yet arrived that any one
particular modern language is universally so thoroughly known that its adoption as the
language of science can be determined upon.

1 Handbuch der Zoologie, 1820, vol. i. p. 599.

2 Bull. Soc. Fhilom. Paris, 1816, p. 122 ; and Journ. de Physique, 1816, vol. Ixxxiii. p. 255.
s Bull. Soc. Philom. Paris, 1814, p. 179.

IIEPORT ON THE LAMELLIBRANCHIATA.

GENERAL REMARKS ON THE COLLECTION.

I have already given a brief notice of the collection, which will be found incorporated
in tlie Narrative of the Voyage,^ and the views there expressed require little modification.

The collection, as a whole, is in some respects disappointing. Considering the
character of the Expedition, the appliances with which it was furnished, the able staff of
scientific men on board, and the number of Stations dredged, it certainly does seem
surprising that only about five hundred species" should have been obtained. This,
however, may not be three-fourths of the number of forms which actually passed into
the dredge or trawl, for doubtless a certain proportion, perhaps a large percentage, of
the secured material, and possibly some of the most valuable, must have found its way
through the meshes of the network during the process of hauling in, especially from
very great depths. Another disappointing feature of the collection is that the species
are represented in tke majority of instances by very few specimens, there being of
many of them but single or a few odd valves, some of which arc in a bad state of
preservation. The greater part of the collection consists of species from comparatively
shallow water, Torres Strait, the Arafura Sea, Port Jackson, Bass Strait, Fiji, Kerguelen
and Marion Islands, supplying a large proportion.

As might be expected, some of the forms are of particular interest when great depths
have been reached, but it is a remarkable fact that only one distinctly new generic type
was discovered.^

The greatest depth at which Lamellibranchs were obtained was 2900 fathoms
(Station 244, in Mid North Pacific). Of the two species from this enormous depth
one is a small fragUe shell which I have named Callocardia i^acijica; I should here
observe, and it is a most interesting fact, that a second species [Callocardia atlantica)
was dredged in 1000 fathoms off the Azores, which is all but identical with that
from the Pacific. A third species of this genus [Callocardia adamsii) was also obtained
in very deep water in the Atlantic to the south-west of Sierra Leone. The second species,
from Station 244, belongs to Ahra, which I regard as a subgenus of Semele.

The other Stations, ranging from depths of 1000 to 2650 fathoms, at which Lamelli-
branchs were obtained are Nos. 45, 47, 56, 70, 71, 73, 78, 85, 98, 104, 106, 113, 133,
135E, 137, 146, 157, 158, 184, 198, 205, 216, 218, 244, 246, 271, 281, 300, 302, 317,
323, 325, and 348. I have quoted these numbers so that reference can be made to the

1 Narr. Cliall. Exp., vol. i. pp. 624-02B, 1S85.

2 This does not include a small number of species represented only by odd valves, which are beyond identification
owing to their younj; state or bad conditidn.

' A still more remarkable absence of generic novelties occurred in the case of the Brachiopoda, not a single ntw
form having been described by Mr. Davidson.

4 THE VOYAGE OF H.M.S. CHALLENGER.

List of Stations given further on, by tliose interested to know the actual species found
in such deep water. I here merely make a few observations respecting the different
genera there met with. At the above thirty-three Stations only twenty-three different
genera were found, although the majority of these occurred in more than one place.
The genera Amussium and Area were met with at seven of the Stations ; Necera at five ;
Lima and Callocardia at four ; Malletia, Limopsis, Cryptodon, Ahra, Lyonsiella, and
Verticordia &tihxe&; Leda, Nucula, Pecten, Silenia, and Sarepta at two; and Modiolaria,
Dacrydium, Pectuncidus, Venus, Myrina, and Glomus at one only.

Some of the species occurred in more than one locality, showing at times a very
remarkable geographical distribution.

The following are some of the principal instances : —

Silenia sarsii,

Saxieam arctica, .

Semele [Abra) profundorum,

Petricola lapieida, .

Venus (Chamelcea) mesodesma,

Cardium siieziense,
Verticordia deshayesiana,

Kellia suborhieidaris, .
Astarte magellanica,
Cardita calyculata,

Nuculina ovalis, .

Sarepta ahyssicola,

Limopsis pelagica,

Area imbricata,

Area {Barbatia) pteroessa,

About 1100 miles south-west of Australia, in 1950

fathoms ; also off the mouth of the Eio de la Plata, in

2650 fathoms.
Cosmopolitan, 0 to 500 fathoms.
Near the Canary Islands, in 1125 fathoms, and Mid

North Pacific, in 2900 fathoms.
North Australia, in 7 fathoms ; a well-known West

Indian form.
New Zealand, on the beach, and off Tristan da Cunha, in

1000 fathoms.
A Red Sea species ; from Fiji, in 12 fathoms.
Off Pernambuco, in 350 fathoms, and near Cape York, in

155 fathoms.
A British species ; from Kerguelen Island, in 28 fathoms.
A Strait of Magellan species ; from ]\Iarion Island.
Off Tenerife, in 70 fathoms, and in Bass Strait, in 38 to

40 fathoms.
A fossil of the Suffolk Crag ; from the Cape of Good

Hope, in 15 to 20 fathoms.
Mid North Pacific, in 2050 fathoms, and Mid South

Pacific, in 2385 fathoms.
Mid Atlantic, in 1850 fathoms, and off Japan, in 345

fathoms.
A West Indian species, from near Cape York, in 25 fathoms.
Mid North Pacific, in 2050 fathoms; west of the Azores,

in 1000 and 1675 fathoms; and the West Indies, in

390 fathoms.

REPORT ON THE LAMELLIBRANCHIATA.

Area {Barbatia) corpulenta,

Mytilus edulis,
Mytilus magellanicus

Modiolaria cuneata,
Lima squamosa,

Lima lata, .

Lima multicostata,

Lima goliaih,

Lima loscomhii,

Pecten vitreus,

North-East Australia, iii 1 400 fathoms ; south of

Amboyna, in 200 to 3G0 fathoms; Mid Pacific, in

2425 fathoms; and near the Lshind of Juan Fernandez,

in 1375 fathoms.
Cosmopolitan.
Falkland Islands, Kerguelen Island, and Fiji, all in

shallow water.
Port Jackson and the Cape of Good Hope, shallow water.
Tenerife, in 70 fathoms, and the Philippine Islands, in

10 fathoms.
St. Paul's Eocks, Atlantic, in 104 fathoms, and

Philippine Islands, in 82 fathoms.
Port Jackson, in 2 to 1 8 fathoms ; Tongatabu, in 1 8

fathoms ; and off Bermuda, in 1075 fathoms.
South Japan, in 775 fathoms, and South Patagonia, in

245 fathoms.
A British species ; from the Azores, in 450 fathoms, and

Tristan da Cunha, in 100 to 150 fathoms.
West coast of Patagonia, in 140 to 400 fathoms ; South

Japan, in 345 fathoms ; and Philippine Islands, in

100 to 700 fathoms.

A perusal of the above will show that some of the species were obtained not only at
widely distant localities, but also at very different depths. Venus mesodesma (a shore
species) was dredged in 1000 fathoms. Area pteroessa in 390 and 2050 fathoms, Lima
midticostata in 2 and 1075 fathoms, Pecten vitreus in 140 and 700 fathoms, Necera ohesa
in 40 and 1000 fathoms, Ervilia castanea in 70 and 1000 fathoms, and Dacrydium
vitreum and Pecten pldlippii, both of which have been obtained in less than 40 fathoms,
were hauled up respectively from 1000 and 450 fathoms. I might multiply examples of
the different ranges in depth at which various species have been obtained by the
Challenger and other expeditions, but those which I have cited are sufficient to show
that the same species is equally well adapted for living in deep or shallow water, and,
as far as I have noticed, the shells appear to be very little aflfected by the difierenee
of the depth or the nature of the bottom.^ As a rule, very deep-water "benthal"
species certainly have a tendency to be without colour, and of thin structure, no
doubt resulting from the absence of light, the difficulty of secreting lime, the scarcity of
food, and other unfavourable conditions of existence.

1 Mr. Davidson has also mentioaed instances of Bracliiopods " capable of existing at a great variety of depth," one
species (Terebratuki vitrea) ranging from 5 to 1456 fathoms. Zool. C'liall. Kxp., part i. p. 6, 1880.

6 THE VOYAGE OF H.M.S. CHALLENGER.

But then most of them belong to genera the species of which from shallow depths
are comparatively thin, and more or less devoid of colour. For instance, I may mention
Necera, Lima, Cr>J2^tod'on, Ahra, Lyonsiella, Verticordia, SarejJta, and DacrijdiuiH.
The deep-water species of such genera as have a decided epidermis (as Mallctia, Limopsls,
Leda, Nucula, and Area) still retain it, with but little if any modification.

From a study of the Challenger collection it would therefore appear that the
Lamellibraneh fauna of the deepest parts of the Atlantic and Pacific Oceans is not of a
very extraordinary, and certainly not of a special, character. The species are apparently
few in number in comparison with those of shallow water, and new and peculiar generic
forms which we naturally expected would have been discovered are of even still i-arer
occurrence.

In support of the theory that Molluscan life is comparatively scarce at great depths,
I may give the following particulars. Species were obtained on forty-three occasions at
depths of less than 100 fathoms, at twenty-four Stations at depths between 100 and 500
fathoms, at ten only in 500 to 1000 fathoms, and at thirty-three in 1000 to 2900 fathoms.
At the diflerent Stations of the first range, 384 ^ species were collected, 148 at those
of the second, 24 at those of the third, and 70 at those of the fourth, so that it will be
seen that the average number of species per Station at the different ranges is as
follows : —

At depths of 0 to 100 fathoms 9 species.
„ 100 to 500 „ 6-16 ,

500 to 1000 „ 2-4 „
1000 to 2900 „ 2-12 „

These figures therefore clearly show that the deeper the Challenger dredged the fewer
were the species obtained.

Mr. Davidson, in his Eeport on the Brachiopoda of the Expedition, has arrived at ii
similar conclusion, for he observes that they " are more numerous both in species and
individuals at depths of less than 500 fathoms," and that it is "apparent that Brachiopoda
do not, as far as our experience goes, generally abound in depths exceeding 500 or 600
fathoms ; for out of one hundred and twenty -five dredgings in depths of from 1 to 600
fathoms, Brachiopoda were brought uji twenty-two or twenty -three times, while in depths
varying from 600 to 2900 fathoms they were obtained about sixteen times."

1 It should be remarkeil that a good many of the species were found at more than one Station, hence the total
number of species here given from those four ranges greatly exceeds the actual number of different species in the
collection.

GEOGEAPHICAL DISTRIBUTION.

The following is a complete list of the Stations at which bivalves were obtained. The
exact latitude and longitude, the depth and the nature of the bottom, will be given in this
place, but not under the "habitat" of each species, so that needless repetition will be
avoided. Only the number of the Station is quoted in the body of the work, but the
geographical position is given to save the reader the inconvenience of constantly referring
back to the subjoined list.

Under each Station are also given the names of the species there obtained, which will
be of use to those interested in the study of special faunas.

The order of the Stations follows the course of the voyage, and such localities as have
no Station number assigned to them follow those numbered Stations to which they are
most closely situated.

Station II.— January 13, 1873 ; lat. 38° 10' N., long. 9° 14' W. ; depth, 470 fathoms ;
bottom, green mud (off the west coast of Portugal).

Limopsis minuta, Philippi. | Pecten sulcatus, var.

Leila rectidorsata, Seguenza (?).

Station VIII.— February 12, 1873; lat. 28° 3' 15" N., long. 17° 27' ^Y. ; depth, 620
fathoms ; bottom, volcanic mud (a little south of the Canary Islands).

Lyonsia formosa, Jeffreys.
JSfecBva teres, Jeffreys.
Montacuta pura, n. sp.

Cryptodqn croulinensis, Jeffreys.
Limopsis minuta, Philippi.
Leda messanensis, Seguenza.

Station 23.— March 15, 1873 ; lat. 18° 24' K, long. 63° 28' W. ; depth, 450 fathoms;
bottom, Pteropod ooze (off Sombrero Island, West Indies).

Necera claviculata, Dall.

Necera sp.
Cryptodon sp.

Limopsis aurita, Brocchi.
Lima {Limatula) confusa, n. sp.
Lima [Limatula) laminifera, n. sp.

Station. — St. Thomas, West Indies ; depth not stated.

Amussium cancellatum, n. sp.

THE VOYAGE OF H.M.S. CHALLENGER.

Station 24.— March 25, 1873 ; lat. 18° 38' 30" N., long. 65° 5' 30" W. ; depth, 390
fathoms; bottom, Pteropod ooze (off Culebra Island, West Indies).

Verticordia ivoodii, n. sp.
Necera consociata, n. sp.
NecBra sp.

Montacuta occidentalis, n. sp.
Cryptodon incrassatus, var.
CrassatcUa parva, C. B. Adams.
Idas dalli, n. sp.
Dacrydium occidentale , n. sp.
Area (Barbatia) pteroessa, n. sp.
Area [ScaiJharea?) incequiseidpta ,

n. sp.
Area (Scapharea ?) culebrensis,

n. sp.
Limopsis minuta, Phili^ipi.
Nucida eulehrensis, n. sp.
Leda deeipiens, u. sp.

Leda inaudax, n. sp.

Leda hebes, n. sp.

Leda despeeta, n. sp.

Malletia veneriformis, n. sp.

Malletia euneata, n. sp.

Glomus ji'ffreysii, n. sp.

Glomus simp>h'x, n. sp.

Glomus incequdatcndis, n. sp.

Glomus S]).

Peeten culebrensis, n. sp.

Peeten sp.

Amussium squamigerum, u. sp.

Amussium ohliquum, n. sp.

Amussium cancellatum, n. sp.

Lima (Limatula) laminifera, n. sp.

Station. — North Atlantic, deep water (probably off Bermuda).

Mo7itaeuta cylindracea, n. sp.

Lucina (Codah'a) tigrina, Linne.

Station 33.— April 4, 1873; lat. 32° 21' 30" N., long. 64° 35' 55" W. ; depth, 435
fathoms ; bottom, coral mud (off Bermuda).

Ciree bermudensis, u. sp.

Ervilia subcancellata, n. s
Verticordia ornata, var.
Corbula philippii, n. sp.
Necera consociata, n. sp.
Necera elavictdata, Dall.
Necera congenita, n. sp.

Station. — Bermuda, depth,-

Lithodomus antillarum, Philippi

Necera curta, Jefireys.
Lucina [CodaJcia) pecfe«, Lamarck.
Cryptodon barbata, Eeeve (?).
Malletia veneriformis, n. sp.
Amussium dalli, n. sp.
Amussium squamigerum, n. sp.
Amussium cancellatum, n. sp.

(?), probably shallow water.

Lithodomus appendieidatus, Philippi.

Station 36.— April 22, 1873; lat. 32° 7' 25" N.
bottom, coral (off Bermuda).
Area noce, Linne.
Area {Aear) domingensis, Lamarck.

long. 65° 4' W.; depth, 30 fathoms ;

Avicula [Meleagnna) squamulosa,
Lamarck.

Lima (Mantellum) Mans, Gmelin.

REPORT ON THE LAMELLIBRANCHIATA.

Station 45.— May 3, 1873; lat. 88° 34' N., long. 72° 10' W.; depth, 1240 fatlioms;
bottom, blue mud (off the east coast of the United States).

Malletia ohtusa, Sars.

Station 47.— May 7, 1873; lat. 41° 14' N., long. G5° 45' W.; depth, 1340 fathoms;
bottom, blue mud (south of Nova Scotia).

Malletia ohtusa, Sars.

Station 56.— May 29, 1873; lat. 32° 8' 45" N., long. 64" 59' 35" W.; depth, 1075
fathoms; bottom, coral mud (oflF Bermuda).

Limopsis awita, Brocchi. | Amussium cancellatum, n. sp.

Lima multicostata, Sowerby.

Station 70.— June 26, 1873; lat. 38° 25' N., long. 35° 50' W.; depth, 1675 fathoms;
bottom, Globigerina ooze (Mid North Atlantic, west of the Azores).

Verticordia tornata, Jeffreys. | Modiolaria semig7'anata, Reeve.

Leda excisa, Philippi.

Station 71.— June 27, 1873; lat. 38° 18' N., long. 34° 48' W.; depth, 1675 fathoms;
bottom, Globigerina ooze (a little east of Station 70).

Area [Barbatia) pteroessa, n. sp.

Station 73.— June 30, 1873; at. 38° 30' N., long. 31° 14' W.; depth, 1000 fathoms;
bottom, Pteropod ooze (a little west of the Azores).

Semele (Ahxi) profundorinn, n. sp.
Callocardia (?) atlantica, n. sp.
Necera circinata, Jeffreys.
NecBra wollastonii, n. sp.

Dacrydium vitreum, MciUer.
Aiva (Barbatia) pteroessa, n. sp.
Limopsis aurita, Brocchi.
Amussium lueidum, Jeffreys.

Station 75.— July 2, 1873; lat. 38° 38' N., long. 28° 28' 30" W.; depth, 450 fathoms;
bottom, volcanic mud (off the Azores).

Cii'ce minima, Montagu.

Venus ( Ventricola) casina,

Linne.
Venus ( Ventricola) effossa, Bivona.
Venus (Chione) ovata. Pennant.

Tellina ( ?) donacina, Linne.

Semele [Abra) longicalUs, Scacchi.
Ervilia castanea, Montagu.
Chama gryphoides, Linne.

(ZOOL. CHALL. ESP. PART XXXV. 1885.)

Cardium {Acanthocardium) papil-
losum, Poli.

Cardium (Paj^yridea) transver-
sale, Deshayes.

Saxicava arctica, Linne.

Necera curta, Jeffreys.

Montacuta pur-a, n. sp.

Cryptodon flexuosus, Montagu.

Area tetragona, Poli.

Mm 2

THE VOYAGE OF H.M.S. CHALLENGER.

Station 75 — continued.

Limopsis minuta, Philippi.
Leda messanensis, Segueuza.
Pccten pusio, Linue.
Pecten phdippii, Edcluz.

Station 78.— July 10, 1873; lat. 37° 26' N
bottom, volcanic mud (oflf the Azores).

Callocardia (?) atlantica, n. sp.
Necera obesa, Loven.
Necera azorica, n. sji.
Cryptodon croidinensis, Jeffreys.
Dacrydium vitreum, MoUer.
Nucula reticidata, Jeffreys.

Station. — Off Tenerife, Canary Islands; depth,

Cytherea {Callista) chione, Linne.
Circe minima, Montagu.
Venus [Ventricola) casina, Linne.
Ventis (Ventricola) effossa, Bivona.
Venerupis irus, Linne.
Psammobia costulata, Turton.
Ervilia castanea, Montagu.
Cliama gryphoides, Linne.
Cardium (Acanthocardium) papil-
losum, Poli.

Pecten testce, Bivona.
Pecten gihhus, Linne.
Lima {Mantellum)
Sowerby.

loscomhii.

long. 25° 13' W.; dejith, 1000 fathoms;

Leda confinis, n. sp.
Leda Jeffrey si, Hidalgo.
Amussium propiiiquum, n. sp.
Amussium litcidiim, Jeffreys.
Lima (Limattda) subovata, Jeffreys.
Lima [Limatula] confusa, n. sp.

70 fathoms.

Cardium [Papyridea) transver-
sal e, Deshayes.
Gastroch(Ena duhia. Pennant.
Diplodonta apicalis, Philippi.
Astarte macandreivi, Smith.
Cardita calycidata, Linne.
Pectunculus stellatus, Bruguiere.
Pecten pusio, Linne.
Pecten corallinoides, d'Orbigny.
Lima squamosa, Linne.

Station 85.— July 19, 1873; lat. 28° 42' N., long. 18° 6' W.; depth, 1125 fathoms;
bottom, volcanic mud (west of the Canary Islands).

Seinele (Abra) profimdorum, n. sp. | Verticordia quadrata, n. sp.

Neasra circinata, Jeffreys.

Station. — St. Vincent, Cape Verde Islands; depth, 7 to 20 fathoms.

Venus (Anaitis) paphia, var.
Psammobia intermedia, Deshayes.
Cardium. {Lcevicardium) norvegi-
cum, var.

Pecten corallinoides, d'Orliigny,

GastrochcBua dubia, Pennant.
Lucina columbella, Lamarck.
Area (Acar) domingensis, Lamarck.
Pectunculus formosus, Eeeve.

REPORT ON THE LAMELLIBRANCHIATA. ' 11

Station 98.— August 14, 1873; lat. 9° 21' N., long. 18' 28' W.; depth, 1750 fathoms;
bottom, Globigerina ooze (west of Sierra Leone, West Africa).

Semele (Abra) 2)rofundorum, n. sp. | Necerajilocarinata, n. sp.

Station 104.— August 23, 1873 ; lat. 2° 25' N., long. 20° 1' W.; depth, 2500 fathoms ;
bottom, Globigerina ooze (Mid Atlantic, between Sierra Leone and North Brazil).

Lima (Limatula) sp.

Station 106.— August 25, 1873 ; lat. 1° 47' N., long. 24° 26' W. ; depth, 1850 fathoms ;
bottom, Globigerina ooze (somewhat west of Station 104).

Verticordia tornata, Jeffreys. | Lyonsiella jeffi-eysii, n. sp.

Limopsis pelagica, n. sp.

Station 109.— August 28, 1873; lat. 0° 55' 38" N., long. 29° 22'35"W.; depth, 104
fathoms ; bottom, hard ground (off St. Paul's Rocks, Mid Atlantic).

Lima lata, n. sp.

Station 113.— September 1, 1873; lat. 3° 40' 45" S., long. 32° 22' W.; depth, 1010
fathoms ; bottom, hard ground (off Fernando Noronha, north-east of Brazil).

Pectuncidus iJectinatus, Gmelin.

Station 11 3a.— September 1, 1873; lat. 3° 47' S. ; long. 32° 24' 30" W. ; depth, 25
fathoms ; bottom, volcanic sand and gravel (anchorage of Fernando Noronha).

Ervilia subcancellata, n. sp.
Cardium (Fragum) medium, Linne.
Lucina [Codahia) p>ecten, Lamarck.

Mytilus exustiis (Lamk.), Reeve.
A7'ca imhricata, Bruguiere.
Pecten noronliensis, n. sp.

Station 120.— September 9, 1873; lat. 8° 37' S., long. 34° 28' W.; depth, 675 fathoms;
bottom, red mud (off Pernambuco, Brazil).

Ervilia subcancellata, n. sp. Leda solidula, n. sp.

Nucida pernambucensis, n. sp. ' Amussium lucidum, Jeffreys.

Lima {Limatula) confusa, n. sp.

Station 122.— September 10, 1873; lat. 9° 5' S.,long. 34°50' W.; depth, 350 fathoms;
bottom, red mud (a little south of Station 120).

Semele obliqua, jun.

Semele (Abra) braziliensis, n. sp.

Verticordia deshayesiana, Fischer.

Verticordia woodii, n. sp.
Mytihis exiistus (Lamk.), Reeve.
Leda semen, n. sp.

Anomia ephipjiium., var.

12 THE VOYAGE OF H.M.S. CHALLENGER.

Station. — Bahia, Brazil ; depth, 7 to 20 fathoms.

Cardium [Papyridea) hullatum (Linne f), Chemnitz.

Station 133.— October 11, 1873; lat. 35° 41' S., long. 20° 55' W.; depth, 1900 fathoms;
bottom, Globigerina ooze (Mid South Atlantic).

Lyonsiella grandis, n. sp. | Cryptodon moselcyi, n. sp.

Station. — Nightingale Island, Tristan da Cunha ; depth, 100 to 150 fathoms.

Venus philomela, n. sp.
Saxicava arctica, Linne.
Diplodonta sp.
CarditeUa exulata, n. sp.

Pecten limatida, var.

Lima (Mantelluin) loscomhii,

Sowerby.
Lima [Limatula) sp.

Anomia ephippiwn, var.

Station 135e.— October 18, 1873; lat. 37° 21' S., long. 12° 22' 30" W. ; depth, 1000
fathoms ; bottom, hard ground, shells, gravel (off Tristan da Cunha).

Venus {Chamelcea) mesodesma, Quoy and Gaimard.

Station 137.— October 23, 1873 ; lat. 35° 59' S., long. 1° 34' E.; depth, 2550 fathoms ;
bottom, red clay (Mid South Atlantic, between Tristan da Cunha and Cape of Good
Hope).

Malletia pallida, n. sp.

Station. — Off the Cape of Good Hope ; depth, 15 to 20 fathoms.

Tellina (Angulus) natalensis,

Krauss.
Cardium (Papyridea) semisulca-

tum, Gray.

Cardita (Thecalia) concamerata,

Chemnitz.
CarditeUa capensis, n. sp.
Nuculina ovalis, Searles Wood.

Station 141.— December 17, 1873 ; lat. 34° 41' S.,long. 18° 36' E.; depth, 98 fathoms;
bottom, green sand (off the Cape of Good Hope).

Saxicava arctica, Linne. I Pecten limatula, var.

Station 142.— December 18, 1873 ; lat. 35° 4' S., long. 18° 37' E.; depth, 150 fathoms ;
bottom, green sand (off the Cape of Good Hope).

Saxicava arctica, Linne. | Nccera capcnsis, n. sp.

REPORT ON THE LAMELLIBRANCHIATA.

Station. — Off Marion and Prince Edward Islands in the Southern Ocean, south-east of
the Cape of Good Hope ; depth, 50 to 300 fathoms.

Davila umhonata, n. sp.
Thracia meridionalis, n. sp.
Saxicava arctica, Linnd.
NecBva fragilissivia, n. sp.
Cryptodon marionensis, u. sp,
Astarte magellanica, n. sp.
Mytilus meridionalis, n. sp.

CreneUa marionensis, n. sp.

Modlolarca trajiezina, Lamarck,

Dacrydium meridionals, n. sp,

Limopsis marionensis, u. sp.

Pecten distinctus, n. sp.

Pecten avicidoides, n. sp.

Lima {Limatula) pygmcea, Philippi.

Station 146.— December 29, 1873; lat. 46° 46' S., long. 45' 31' E. ; depth, 1375
fathoms ; bottom, Globigerina ooze (Mid Southern Ocean).

Pecten pudicus, u. sp. | Amussium meridionale, n. sp.

Station. — Kerguelen Island; depth, shore to 120 fathoms; bottom, volcanic mud.

Davila (?) umhonata, n. sp.
Anatina elliptica, jun.
Tliracia meridionalis, n. sp.
Necera kerguelensis, n. sp.
Kellia suhorhicidaris, Montagu.
Kellia cardiformis, n. sp.
Kellia nuculina. Martens,
Cardita astartoides, Martens,

Mytilus kerguelensis, n. sp.
Mytilus magella n icus, Chemnitz.
Modiolarca trapezina, Lamarck.
Modlolarca kerguelensis, n. sp,
Yoldia isonota, Martens.
Yoldia subcequilctteralis, Smith.
Malletia gigantea, Smith.
Pecten clathratus, Martens,

Lima [Limatula) pygmcea, Philippi.

Station 150.— February 2, 1874 ; lat. 52° 4' S., long. 71° 22' E. ; depth, 150 fathoms;
bottom, coarse gravel (south-east of Kerguelen Island).

Saxicava arctica, Linne.
Cardita astartoides, Martens,

Mytilus meridionalis, n. sp.
Limoj)sis straminea, n. sp.

Station 157.— March 3, 1874; lat. 53° 55' S., long. 108° 35' E.; depth, 1950 fathoms;
bottom. Diatom ooze (Mid Ocean, south-west of Australia).

Lyonsiella papyracea, n. sp. | Silenia sarsii, n. sp.

Necera meridionalis, n. sp.

Station 158,— March 7, 1874; lat. 50° 1' S., long. 123° 4'E.; depth, 1800 fathoms;
bottom, Globigerina ooze (somewhat north-east of preceding Station).

Amussium meridioncde, n, sp.

THE VOYA.GE OF H.M.S. CHALLENGEK.

Station 161.— April 1, 1874; lat. 38° 22' 30" S., long. 144' 36' 30" E.; depth, 33
fathoms ; bottom, sand (oif the entrance to Port Philip, South Australia).

Cardmm (Bucardium) 'pulchellum,
Gray.

Leda crassa, Hinds.
Leda ensicula, Angas.

Station 162.— April 2, 1874 ; lat. 39° 10' 30" S., long. 146° 37' E.; depth, 38 fathoms ;
bottom, sand and shells (off East Moncoeur Island, Bass Strait).

Cytherea (Callista) rutila, Sowerby.
Venus (CJiione) striatissima,

Sowerby.
Thracia ivatsoni, n. sp.
Thracia myodoroides, u. sp.
Myochama anomioides, Stutchbury.
Cardium [Bucardium) pidchellum,

Gray.
Kellia rotunda, var.
Cardita calyculata, var.
Cardita dilecta, n. sp.
Cardita beddomei, n. sp.

Cardita himacidata, Deshayes.
Crassatella aurora, A. Adams and

Angas.
Trigonia margaritacea, Lamarck.
Area (Barhatia) radtda, A. Adams.
Pectuncidus beddomei, n. sp.
Limopsis hassi, n. sp.
Pinna tasmanica, Ten. Woods (?).
Peeten asperrimus, Lamarck.
Pecten undidatus, Sowerby.
Lima (Limatula) bullata, Born.

Station. — Port Jackson, Sydney ; depth, shallow water, 2 to 35 fathoms.

Dosinia circinaria, Deshayes.
Cytherea (CalUsta) disrwpta,
Sowerby.

Circe scri])ta, Linne.

Circe australis, Angas.

Venus (Chione) calophylla^ Philippi.

Vemis [Chione) jacksonii, n. sp.

Venus [Chione) striatissima,

Sowerby.
Venus [Leukoma) australis,

Sowerby.
Tapes [Paratapes) textrix, Chemnitz.
Tapes [Amygdala) fabagclla,

Deshayes.
Psammobia zonalis, Lamarck.
Saxicava arctica, Linne.
Solen sloanii. Gray.
Corbula truncata. Hinds.

Neaira bi-azieri, n. sp.

Kellia rotunda, var.

Kellia adamsi, Angas.

Montacuta angasi, n. sp.

Lucina ramsayi, n. sp.

Lucina [Loripes ?) jacksonensis,n. sp.

Diplodonta sp.

Cardita sp.

Psammobia modesta, Deshayes.

Tellina [ ?) semitorta, Sowerby.

Donax nitidus, Deshayes.
Mactra [Trigonella) imsilla,

A. Adams.
Mactra [Trig07iella) jachsonensis,

n. sp.
Mactra [Mactrinula) depressa,

Eeeve.
Ervilia hisctdpta, Gould.

REPORT ON THE LAMELLIBRANCHIATA.

Station. — Port Jackson, Sydney — continued.
Chama splnosa, Broderip.
Thracia modestn, Angas.
Myodora ixindoriformis, Stutcli-

bury.
Myodora hrcvis, Sowerby.
Myodora crassa, Stutchbiuy.
Myodora australis, Reeve.
Myodora angustata, Angas.
Myochama anomioides, Stutclibnry.
Cardium (Bucardium) tenuicos-

tatum, Lamarck.
Cardium (Bucardium) pidchellum,

Gray.
Cardita excavata, Deshayes.
Carditella angasi, n. sp.
Mytilus hirsutus, Lamarck.

ModioJa glaberrima, Dunker.
ModioJaria laniger, Dunker.
Modiolaria cumingiana, Dunker.
Modiolaria vancosa, Gould.
Modiolaria cuneata, Gould.
Trigonia lamarckii, Gray.
Area (Barhatia) fasciata, Eeeve.
Aixa {Scapharca) gubernacidum,

Reeve.
Pectuncidus holosericus, Reeve.
Pectuncidus s(na<MZaW.9,Lamarck(?).
Limopsis hrazieri, Angas.
Pecten [Janira) fumatus, Eeeve.
Lima multicostata, Sowerby.
Lima angulata, Sowerby.
Lima (Limatida) hullata, Born.

Station 164.— June 12, 1874 ; lat. 34° 8' S., long. 152° E.; depth, 950 fathoms; bottom,
green mud (off the coast of New Soiith Wales).

Leda inojiinata, n. sp. | Leda ramsayi, n. sp.

Station 164b.— June 13, 1874; lat. 34° 13' S., long. 151° 38' E.; depth, 410 fathoms;
bottom, green mud (off the coast of New South Wales).

Necera angasi, n. sp.

Station 167a.— June 27, 1874; lat. 41° 4' S., long. 174° 19' E.; depth, 10 fathoms;
bottom, mud (Queen Charlotte Sound, New Zealand).

Dosinia lamhata, Gould.
Cytherca (Callista) multistriata,

Sowerby.
Psammohia lineolata, Gray.

Station. ^D'Urville Island, New Zealand ; shore.
Venus ( Chamelcea) mesodesma,
Quoy and Gaimard.

Tellina {TellineUa) charlottce^

n. sp.
Tellina [TellineUa) huttoni, n. sp.
Nuctda nitidida, A. Adams.

Tapes (Amygdala) intermedia,
Quoy and Gaimard.

Mytilus edulis, Linne.

Station 169.— July 10, 1874; lat. 37° 34' S., long. 179° 22' E.; depth, 700 fathoms;
bottom, blue mud (off" the north-east coast of New Zealand).

Limopsis lata, n. sp.

THE VOYAGE OF H.M.S. CHALLENGER.

Station 171.— July 15, 1874; lat. 28° 33' S., long. 177° 50' W.; depth, GOO fathoms;
bottom, hard ground (north of the Kermadec Islands),

Pecten kermadecensis, n. sp.

Station 172.— July 22, 1874; lat. 20° 58' S., long. 175° 9' W.; depth, 18 fathoms;
bottom, coral mud (off Tongatabu).

Venus [Antigona) puerpera, var.

Circe arnica, n. sp.

Psammohia pulcherrima, Des-

hayes.
Psammohia castrcnsis, Spengler.
TelUna (Tdlinella) verrucosa,

Hanley.

Chama brassica, Reeve.
Cardium (Fragum) fornicatum,

Sowerby.
Corhula modesta. Hinds.
Lucina (CodaJcia) interrupta,

Lamarck.
Pecten amicus, n. sp.

Lima midticostata, Sowerby.

Station. — Fiji Islands ; depth, 0 to 12 fathoms.

Cytherea (Dione) philipjoinarum,

Hanley.
Circe sulcata, Gray.
Circe gordoni, n. sp.
Venus {Chione) marica, Linnd.
Venus (Chione) levukensis, n. sp.
TeJlina (Angidus) valtonis,

Hanley.
Tellina (Arcojyagia) j^^reiioscf,

Deshayes.
Tellina ( f) rJiomboides,

Quoy and Gaimard.
Tellina ( f) tenuilirata,

Sowerby.
Tellina ( ?)Jijiensis, Sowerby.

Tellina ( ?) semen, Hanley.

Cardium (Acanthocardium) suezi-
ense, Issel.

Cardium [Bucardium) australe,
Sowerby.

Lucina (Codakia) levukana, n. sp.

Lucina (Codakia) Jijiensis, n. sp.

Lucina (Loripes ?) gordoni, u. sp.

Cryptodon rufolineata, u. sp.

Mytilus magellanicus, Chemnitz.

Septtifer hiloctdaris, Linne.

Area (Barhatia) fusca, Bruguiere.

Leda micans. A. Adams.

Lima (Ctenoides) tenera, Chem-
nitz.

Station 184.— August 29, 1874 ; lat. 12° 8' S., long. 145° 10' E.: depth, 1400 fathoms;
bottom, Globigerina ooze (east of Cajie York, North Australia).

Teredo sp.

Myrina coppingeri, n. sp.

A7-ca (Barhatia) corpulenta, n. sp.
Pecten murrayi, n. sp.

REPORT ON THE LAMELLIBRANCHIATA.

Station 185.— August 31, 1874; lat. 11° 35' 25" S., long. 144° 2' E. ; depth, 135 fathoms;
bottom, coral sand (east of Cape York, North Australia).

Tellina (• ?) d'duta, n. sp.

Semele {Abra) regidaris, n. sp.
Verticordia deshayesiana, Fischer.
Verticordia australiensis, n. sp.
NecBra fallax, n. sp.

Station 185b.— August 31, 1874; lat. 11° 38' 15" S., long. 143° 59' 38" E
fathoms; bottom, coral sand (east of Cape York, North Australia).

Poromija australla, n. sp.
Poromija Icevis, n. sp.
Nucula torresi, n. sp.
Leda watsoni, n. sp.
Leda necBriformis, n. sp.

depth, 155

Tellina murrayi, n. sp.
Montacuta acuminata, n. sp.
I/iicina cristata, n. sp.

Lucina (Codakia) congenita, n. sp.
Limopsis torresi, n. sp.
Amussium torresi, n. sp.

Station 186.— September 8, 1874 ; lat. 10° 30' S., long. 142° 18' E.; depth, 8 fathoms;
bottom, coral mud (Cape York).

Circe ohliquissima, n. sp.
Venus {Chione) foliacea, Philippi.
Chamajukesii, Eeeve.
Tridacna crocea, Lamarck.
Gastrochcena lameUosa, Deshayes.
Corbida monilis, Hinds.

Lima (Limatula) torresiana, n. sp

Station. — Cape York, in 3 to 12 fathoms.
Circe fastigiata, Sowerby.
Psammobia anomala, Deshayes.
Tellina [Aiigidus?) rhomhoidcs,

Quoy and Gaimard.
Mactra {Mactrinida) pUcataria,

Linne.
Cardiu m (Fragum) imhricatum,

Sowerby.

Mytilus (Stavelia) horridus, Dunker.
Lithodomus malaccanus, Reeve.
Area (Barhatia) lima. Reeve.
Limopsis caiicellata, Reeve.
Avicnla macroptera, Lamarck.
Spondylus zonalis, Lamarck.

Lucina {Divaricella) irpex, n. sp.
Mytilus sidcatus, Lamarck.
Trigonia uniopJiora, Gray.
Area navicular is, Bruguiere.
Limopsis cancellata, Reeve.
Malleus albv^, Lamarck.
Avicula {Meleagrina)
dina, Reeve.

smarag-

Station.— Flinders Passage, north of Cape York ; depth, 7 fathoms.

Dosinia histrio, Gmelin.
Petricola lapicida, jun.

Tellina ( ?) tenuilirata,

Sowerby.

Tellina ( '?*) languida, n. sp.

Tellina ( f) semen, Hanley.

Semele infans, n. sp.

(ZOOL. CHALL. EXP. PART XXXV. 1885.)

Myodora trigona, Reeve.

Myodora sp.

Mya sp.

Ccelodon elongata. Carpenter.

Diplodonta, subglobosa, n. sp.

Diplodonta conspicua, n. sp.

Limopsis cancellata, Reeve.

Mm 3

THE VOYAGE OF H.M.S. CHALLENGER.

Station. — Torres Strait; depth, 3 to 11 fathoms.

Dosinia sculptd, Hauley.
Cytlierea [Carr/atis) coxeni, Smith.
Ci/th erea ( Gary a tis) regularis, n. sp.
Circe scripta, Linud.
Venus (Antigona) lamcllaris,

Schumacher.
dementia papyracea, Gray.
Tellina (Arcopagia) elegantissima,

n. sp.

Tellina (-
Tellina (-

f) casta, Hauley.
?) langvida, n. sp.

Clavagella torresi, n. sp.
Corhula crassa, var.
Corhula scajjJwides, Hinds.
Diplodonta conspicua, n. sp.
Area {Scapharca) clathrata, Eeeve.
Area (Trisis) semitoi'ta, Lamarck.
Nucula ohliqua, Lamarck.

Station 187.— September 9, 1874 ; kt. 10°
bottom, coral mud (Torres Strait).

Dosinia deshayesii, A. Adams.
Dosinia histrio, Gmelin.
Venus torresiana, Smith.
Venus (Chione) foliacea, Phil-

ippi.
Venus {Chione) calophylla, Phil-

ippi-
Vemcs [Chione) infans, u. sp.

Venus ( Gomphina) undulosa,

Lamarck.

Tellina compacta, n. sp.

Tellina ( ?) semen, Hauley.

36' S., long. 141° 55' E.; depth, 6 fathoms;

Donax nitidus, Deshayes.
Chama sidphurea, Reeve.
Myodora, sp. (also Station 188).
Corhula monilis, Hinds.
Diplodonta scalpta, n. sp.
Diplodonta corpulenta, n. sp.
Diplodonta subglobosa, n. sp.
Diplodonta conspicua, n. sp.
Crassatella rhoniboides, n. sp.
Area imhricata, Bruguiere.
Avicula (Meleagrina) muricata,
Eeeve.

Station 188.— September 10, 1874; lat. 9° 59' S.^
bottom, green mud (south of New Guinea).

Cytherea (Caryatis) regularis, n. sp.
Circe australis, Sowerby.
Circe gibhia, Lamarck.
Circe jucunda, n. sp.
Venus (Chione) foliacea, Pliilippi.
Venus (Chione) lionota, n. sp.
Venus (Chione) infans, n. sp.
Tapes (Paratapes) semirugata,

Pbilippi.
Psammobia pallida, Desbayes.

long. 139° 42' E.; depth, 28 fathoms;

Tellina ( ?) tenuilamellata,

n. sp.
Myodora sp. (also Station 187).
Cardium (Bucardium) multi-

spinosum, Sowerby.
Cardium (Fragum) torresi, n. sp.
Solen (Azor) coarctatus, Gmelin.
Corbida macgillivrayi, n. sp.
Corbida monilis. Hinds.
Montacuta paula, A. Adams.

REPORT ON THE LAMELLIBRANCHIATA.

Station 188 — continued.

Lucina [Codakia) semimda, Gould.
Lucina {Codakia) pisuin, Reeve.
Lucina (Loripes) desiderata, n. sp.
Dijdodonta corpulenta, n. sp.
Diplodonta conspicua, n. sp.
Canlita insignis, n. sp.
Carditella torresi, n. sp.
Car'ditella infans, n. sp.
Crassatella rhomboides, u. sp.
Crassatella torresi, n. sp.

Trigonia iiniop>hora, Gray.
Pectuncidus vitreus, Lamarck.
Limopsis cancellata, Reeve.
Nuc^da ohliqua, Lamarck.
Leda novce-guineensis, n. sp.
Leda corhidoldes, n. sp.
Spondylus victorice, Sowerby.
Amussium pleuronectes, Linne.
Amussium scitulum, n. sp.
Ostrea imhricata, Lamarck.

Station 189.— September 11, 1874 ; lat. 9° 36' S., long. 137° 50' E. ; depth, 25 fathoms ;
bottom, green mud (Arafura Sea).

Dosinia histrio, Gmelin.

Dosinia mira, n. sp. '

Tapes (Paratapes) undulata,

Born.
Tellina (Angulus) lux, Hanley.
Semele amabilis, A. Adams.

Cardium [Bucardiinn) nndtispin-

osum, Sowerby.
Necera elegans. Hinds.
Corhida tunicata. Hinds.
Trigonia uniophora, Gray.
Area (Scapharca?) consociata,ii. sp.

Leda lata, Hinds.

Station 190.— September 12, 1874 ; kt. 8° 56' S., long. 136° 5' E. ; depth, 49 fathoms ;
bottom, green mud (Arafura Sea).

Tellina {Macoma) arafurensis,n. sp. 1 Martesia striata, Linne.

Station 191.— September 23, 1874; lat. 5° 41' S., long. 134° 4' 30" K; depth, 800
fathoms ; green mud (near the Arrou Islands).

Modiola watsoni, n. sp. | Nucula sp.

Malletia arrnana, n. sp.

Station. — Banda Islands; depth, shallow water.
Cytherea (Dione) pliilippinarum,
Hanley.

Mactra [Trigonella decoi^a), juu.

Station 194.— September 29, 1874; lat. 4° 34' S., long. 129° 57' 30" E.; depth, 200
fathoms; bottom, volcanic mud (south of the Molucca Islands).

Area (Barhatia) corpidenta, n. sp.

20 THE VOYAGE OF H.M.S. CHALLENGER.

Station. — Amboina, Molucca Islands; depth, 15 to 20 fathoms.

Venus (Chione) lionota, var.
Tapes (Paremhola) ohscurata,

Dcshayes.
Psammobia sp.
Tellina (Angulus) vernalis,

Hanley.
Tellina (Macoma) consociata,

n. sp.
Semele [Theora) iridescens, Hiuds.

Corhda tunicata, Hinds.
Corhula modesta, Hinds.
Liicina (Codakia) sp. jiin.
Cryptodon bidhda, Eeeve.
Dijflodonta amboinensis, u. sp.
Area (Barbatia) sculptilis, Reeve.
Area (Seapharca) clathrata,

Reeve.
Plicatida sp.

Station 198.— October 20, 1874; lat. 2° 55' N., long. 124° 53' E.; depth, 2150
fathoms ; bottom, blue mud (off the north-east point of Celebes).

Area {Barbatia) corpulenta, n. sp.

Station 201.— October 26, 1874; lat. 7° 3' N., long. 121° 48' E.; depth, 82 fathoms;
bottom, stones, gravel (off the west coast of Mindanao, Philippine Islands).
Venus [Chione) mindanensis, n. sj). | Area (Acar) eongenita, n. sp.

Lima lata, n. sj?.

Station. — Off Samboangan, Philippine Islands; depth, 10 fathoms.

Perna samoensis, Baird. | Pecten lemniscatus, Reeve (?).

Station 203.— October 31, 1874; lat. 11° 6' N., long. 123° 9'E.; depth, 20 fathoms;
bottom, mud.

Peeten senatorius, var.
Amussium pleuroneetes, Linn^.

Venus [Chione) calophylla, Philippi.
Cardium [Bucardium) mirabile,
Deshayes.

Station 204.— November 2, 1874; lat. 12° 28' N., long. 122° 15' E.; depth, 705 fathoms;
bottom, green mud (off the west coast of Luzon, Philippine Islands).

Peeten vitreus, Chemnitz.

Station 205.— November 13, 1874; lat. 16° 42' N., long. 119° 22' E.; depth, 1050
fathoms; bottom, blue mud (same as preceding Station).

Cryptodon luzoniea, n. sp.

Station 207.— January 16, 1875; lat. 12° 21' N., long. 122° 15'E.; depth, 700 fathoms;
bottom, blue mud (west of the Island of Luzon).

Modiola ivatsoni, n. sp. | Pecten vitreus, n. sp.

Amussium caducum, n. sp.

REPORT ON THE LAMELLIBRANCHIATA.

Station 208.— January 17, 1875; kt. 11° 37' N., long. 123° 31' E.; depth, 18 fathoms;
bottom, bhxe mud (same as Station 204).

Chama cardit(Bfo7-mis, Eeeve.
Anatina siphonata, Eeeve.

Cardium (Bvcardivvi) tenuicos-

tatum, Lamarck.
Cardium {Bucardiiim) aiidrale,

Sowerby.

Diplodonta suhgramdosa, n. sp.
Area (Barbatia) lima, Reeve.
Pecten leopai-dus (var. Solaris).
Pecten senatoriits, var.

Station 209.— January 22, 1875 ; lat. 10° 14' N., long. 123° 54' E. ; depth, 95 fathoms;
bottom, blue mud (east of the Island of Panay, Philippines).

Pecten viirens, Chemnitz.

Station 210.— January 25, 1875 ; lat. 9° 26' N., long. 123° 45' E. ; depth, 375 fathoms;
bottom, blue mud (same position as Station 209).

Semele (Abt'a) philippinensis, n. sp. | Amussium jeffreysii, n. sp.

Station 212.— January 30, 1875 ; lat. 6° 54' N., long. 122° 18' E. ; depth, 10 fathoms;
bottom, sand (south of the Island of Mindanao).

Cytherea {Callista) Ulacina,

Lamarck.
Cytherea (Callista) roseotincta, n. sp.
Cytherea (Caryatis) hebrcea,

Lamarck.
Cii'ce sulcata, Gray.
Venus (Chione) recognita, n. sp.

Mactra (Trigonella) incarnata,

Deshayes.
Cardium setosum, Redfield.
Cardita canalicidata, Reeve.
Area [Scapharca) angieostata,

Reeve.
Pectunculus st7-iatidaris,hamsLTck (?).

Lima squamosa, Lamarck.

Station 216.— February 16, 1875; lat. 2° 46' N., long. 133° 58' E. ; depth, 1675
fathoms ; bottom, Globigerina ooze (north-west of New Guinea).

Ai-ca (Barbatia) corpulenta, n. sp.

Station 218.— March 1, 1875; lat. 2° 23' S., long. 144° 4' E. ; depth, 1070 fathoms;
bottom, blue mud (north of New Guinea).

Amussium watsoni, n. sp.

Station 219.— March 10, 1875; lat. 1° 54' S., long. 146° 39' 40" E. ; depth, 150
fathoms ; bottom, coral mud (a little north-east of Station 218).

Cryptodon watsoni, n. sp.

22 THE VOYAGE OF H.M.S. CHALLENGER.

Station. — Admiralty Islands; depth, IG to 25 fathoms.

Mactra [Trigondla) achatina,
Chemnitz.

Mactra (Trigonella) incerta,
n. sp.

Station 232.— May 12, 1875; lat. 35° 11' K, long. 139° 28' E. ; depth, 345 fathoms;
bottom, green mud (Gulf of Yedo, Japan).

Limopsis pelagica, u. sp.
Nucula niponica, n. sp.

Yoldia lischkei, n. sp.
Pecten vitreus, Chemnitz.

Station. — Off Yokohama, Japan; depth, 8 to 14 fathoms.

Raeta pulchella, A. Adams and Eeeve.

Station 233a.— May 10, 1875; lat. 34° 38' N., long. 135° 1' E.; depth, 50 fathoms;
bottom, sand (between the islands of Sikok and Nipon, Japan).

Venus (Chione) scahra, Hanley.
Tapes {Chione) undulata, Born.
Modiola harhata, Liune.
Area (Maerodon) dalli, n. sp.

Nucula (Acila) mirahilis, Adams

and Eeeve.
Pecten (Janira) laqueatus,

Sowerby.

Anomia laqueata, var.

Station 233c.— May 28, 1875; lat. 34° 18' K, long. 133° 21' E.; depth, 12 fathoms;
bottom, blue mud (same as preceding Station).

Paeta pulchella, Adams and Eeeve.

Station 236.— June 5, 1875; lat. 34° 58' N., long. 139° 29' E.; depth, 775 fathoms;
bottom, green mud (south-east of Nipon, Japan).

Lima goliath, Sowerby.

Station 244.— June 28, 1875; lat. 35° 22' N., long. 169° 53' E.; depth, 2900 fathoms;
bottom, red clay (Mid North Pacific Ocean).

Semele (Abra) profimdorum,!!. SI). | Callocardia {?) pacifica, n. sp.

Station 246.— July 2, 1875; lat. 36° 10' N., long 178° E.; depth, 2050 fathoms;
bottom, Globigerina ooze (Mid North Pacific Ocean).

Area [Barhatia) pteroessa, n. sp. | Nucidd profundorum, n. sp.

Sarep)ta ahyssicola, n. sp.

Station. — ^Honolulu, Sandwich Islands (off the reefs in 40 fathoms).

Circe jucunda, n. sp.
Ervilia sandwichensis, n. sp.

Liicina (Codakia) hawaiensis, n. sp.
Julia exqu'isita, Gould.

REPORT ON THE LAMELLIBRANCHIATA. 23

Station. — Honolulu; depth?

Ervilia hisculpta, Gould. | Perna samoemis, Baird.

Station. — Hilo, Sandwich Islands ; depth?

Perna vitrea, Eeeve.

Station 271.— September 6, 1875; lat. 0° 33' S., long. 151° 34' W.; depth, 2425
fathoms; bottom, Globigerina ooze (Mid Pacific Ocean).

Area (Barhatia) corpulenta, n. sp.

Station. — Tahiti ; depth, 20 to 40 fathoms.

Cytherea (Dione) philijypinarum,
Hanley.

LiTna tahitensis, n. sp.

Station 281.— October 6, 1875; lat. 22° 21' S., long. 150° 17' W. ; depth, 2385 fathoms ;
bottom, red clay (Mid South Pacific Ocean, south of Tahiti).

Sarepta abyssicola, n. sp.

Station 300.— December 17, 1875; lat. 33° 42' S., long. 78° 18' W.; depth, 1375
fathoms; bottom, Globigerina ooze (a little north-east of Juan Fernandez).

Area (Barbatia) corpulenta, n. sp.

Station 302.— December 28, 1875; lat. 42° 43' S., long. 82° 11' W.; depth, 1450
fathoms; bottom, Globigerina ooze (about 600 miles west of Chili).

Amussium meridionale, n. sp.

Station 305.— January 1, 1876, lat. 47° 47' S., long. 74° 47' W.; depth, 165 fathoms;
bottom, blue mud (ofli" the west coast of Patagonia).

NecBra patagonica, n. sp.

Station 307.— January 4, 1876; lat. 49° 24' 30" S., long. 74° 23' 30" W.; depth, 140
fathoms ; bottom, blue mud (off the west coast of Patagonia).

Pecten vitreus, Chemnitz.

Station 308.— January 5, 1876; lat. 50° 8' 30" S., long. 74° 41' W.; depth, 175
fathoms; bottom, blue mud (same as Station 307).

Pecten vitreus, Chemnitz.

24 THE VOYAGE OF H.M.S. CHALLENGER.

Station 310.— January 10, 1876; lat. 51° 27' 30" S., long. 74° 3' AV.; depth, 400
fathoms; bottom, blue mud (off the west coast of Patagonia).

Pecten vitreus, Chemnitz. | Pecten suhhyalinus, n. sp.

Station 311.— January 11, 1876; lat. 52° 45' 30" S., long. 73° 46' W.; depth, 245
fathoms; bottom, blue mud (off west coast of Southern Patagonia).

Saxicava arctica, Linne. Modiolarca trapezina, Lamarck.

Solemya patagonica, u. sp. Pecten vitreus, Chemnitz.

Lucina lamellata. Smith. Lima goliath, Sowerby.

Station 312.— January 13, 1876; lat. 53° 37' 30" S., long. 70° 56' W.; depth, 9 fathoms;
bottom, blue mud (Strait of Magellan).

Pecten patagonicus, King.

Station 313.— January 20, 1876; lat. 52° 20' S., long. 67° 39' W.; depth, 55 fathoms;
bottom, sand (east of the entrance to the Strait of Magellan).

Saxicava arctica, Linne.

Station 315.— January 26, 1876; lat. 51° 40' S., long. 57° 50' W.; depth, 12 fathoms
(off the Falkland Islands).

Mijtilus ediilis, Linn^.

Mytilus magellanicus, Chemnitz.

Modiolarca trapezina, Lamarck.
Pecten piatagonicns, King.

Station 316.— February 3, 1876; lat. 51° 32' S., long. 58° 6' W. ; depth, 4 fathoms;
bottom, mud (off the Falkland Islands).

Venus (Katelysia) exalhida, Chem-
nitz.

Cryptodon falhlandica, n. sp.

Station 317.— February 8, 1876; lat. 48° 37' S., long. 55° 17' W.; depth, 1035 fathoms;
bottom, hard ground (gravel) (north of the Falkland Islands).

Lima (Limatula) sp.

Station 320.— February 14, 1876; lat. 37° 17' S., long. 53° 52' W.; depth, 600 fathoms;
bottom, green sand (off the coast of La Plata).

Neoera platensis, n. sp.

REPORT ON THE LAMELLIBRANCHIATA. 25

Station 321.— February 25, 1876; lat. 35° 2' S., lung. 55° 15' W.; depth, 13 fathoms;
bottom, mud (mouth of the Rio de la Plata).

Cytherea (Caryatis) rostrata,

Koch
Tellina (Macoma) uruguayensis,

n. sp.

Mactra {Trigonella) isahelliana,

d'Orbigny.
Periploma compressa, d'Orbiguy.
Nucula uruguayensis, Smith.

Station 322.— February 2G, 1876; lat. 35° 20' S., long. 53° 42' W.; depth, 21 fathoms;
bottom, sand, shells (off the mouth of the Rio de la Plata).

Mytilus edulis, Linne. | Plicatula r-ainosa, Lamarck.

Station 323.— February 28, 1876; lat. 35° 39' S., long. 50° 47' W. ; depth, 1900 fathom.s;
bottom, blue mud (east of the preceding Station).

Glomus nitens, Jeffreys.

Station 325.— March 2, 1876 ; lat. 36° 44' S., long. 46° 16' W.; depth, 2650 fathoms;
bottom, blue mud (farther east than Station 323).

Silenia sarsii, n. sp.

Station 344.— April 3, 1876; lat. 7° 54' 20" S., long. 14° 28' 20" W.; depth, 420
fathoms ; bottom, volcanic sand (off Ascension Island).

Cryptodon sp. | Leda Jeffrey sii, Hidalgo.

Station 348.— April 9, 1876; lat. 3° 10' N., long. 14° 51' W.; depth, (2450) fathoms;
bottom, Globigerina ooze (south of Sierra Leone).

Callocardia (f) adamsii, n. sp.

(ZOOL. CHALI.. EXP. — PART XXXV. — 188-5.) Mm 4

DESCRIPTIONS OF SPECIES.

Order LAMELLIBRANCHIATA.

Family Pholadid^.

Subfamily Teredinin^.

Teredo, Linne.
Teredo sp.
Habitat. — Station 184, east of Cape York (in 1400 fathoms ?) ; Globigerina ooze.

A single very small specimen, all that was obtained, may possibly be the young state
of the Teredo mentioned in the Eeport of the collections made during the Voyage of
H.M.S. "Alert" in Torres Strait. The striae on the anterior part of the valves are,
however, rather coarser. Although from Station 184, to which a depth of 1400 fathoms
is assigned, it seems probable that this sheU, which contained the animal, got into the
trawl near the surface, during the process of hauling in. This, however, is not certain,
for water-logged wood might be found at that depth into which it might bore.

Subfamily PnoLADiNiE.
Martesia, Leach.

Martesia striata (Linne).

P?wlas striata (Linne), Sowerby, Thesaurus Conch., vol. ii. p. 494, pi. civ. figs. 40-42, pL cv.

figs. 43, 44.
Pholas striata, Sowerby, Conch. Icon., vol. xviii. figs. 32a-c.
MaHesia striata, II. ami A. Adams Genera, vol. iii. pi. xc. figs. 5, 5a.

Habitat. — Station 190, Arafura Sea, in 49 fathoms; green mud.

Specimens from this locality present very slight if any variation in sculpture, but
difl'er somewhat in the length of the hinder prolongation of the valves, and in the form
of the anterior dorsal plate.

28 THE VOYAGE OF H.M.S. CHALLENGER.

Subfamily (iASTROCH^NiN^.
Gastrochcena, Spengler.
Gastrochcena lamellosa, Desliayes (PI. VIII. figs. 2-2&).

Gastrochcena lamellosa, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 328.
Gasfrochceiia lamellosa, Sowerby, Conch. Icon., vol. xx. fig. 14 (bad !).

Habitat. — Station 18G, off Cape York, in 8 fatliom.s (Challenger); coral mud;
Island of Zebu, Philijipines (Cuming).

The figure in Sowerby's Monograph is not at all accurate, neither as regards the form-
of the gape nor the opposite extremity. The figure now given is taken from the type
specimen in the British Museum.

Gastrochcena duhia (Pennant).

My a duhia. Pennant, Brit. Zool., voL iv. p. 88, pi. xliv. fig. 19.

Gastrochcena rnodiolina, Lamarck ; Forbes and Hanle}', Brit. Moll., vol. i. p. 132, pi. ii. figs. 5-8,

and PI. F. fig. 5 (animal).
Gastrochcena duhia, Deshayes, Traits Elem. Couch., pi. ii. 6gs. 4, 5.
Gastrochcena duhia, Jeffreys, Brit. Conch., vol. iii. p. 91, vol. v. pi. Ii. fig. 6.
Gastrochcena dubia, Hidalgo, Molusc. Espaiia, pi. xlix. figs. 3, 4.

Habitat. — Harbour of St. Vincent, Cape Verde Islands and Tenerife, Canaries, in 70
fathoms.

This species, ranging from the southern coasts of England to the Mediterranean,
Madeira, and Canary Islands, has not, I believe, hitherto been noticed so far south as the
Cape Verde Islands. The single specimen from that locality is a trifle more elongate
than those from Tenerife.

Subfamily Clavagellin.e.
Clavagella, Lamarck.

Clavagella torresi, n. sp. (PL VIII. figs. l-\h).

Testa parva, tenuis, allia. Valva liliera valde insefjuilateralis, antice late rotundata,
postice paulo angustior, lineis incrementi subrugosis sculpta, liris tenuissimis granulosis
radiantibus umbones versus ornata. Pagina interna nitens, concentrice alicpianto rugosa,
radiatim indistincte substriata. Ligamentum internum parvum, oblicj[Uum, postice deuticuh >
minuto terminatum. Tubus inferne irregulariter ovatus, superne valde constrictus ct
angustatus, ad basim c[uoque ad latera tubulis multis instructus.

REPORT ON THE LAMELLIBRANCHIATA. 29

Of this small species only a single specimen was dredged. The lower portion of the
tube is somewhat ovate, and broader at the inferior end. Above it is rather suddenly-
contracted into a small, i)lain tube, which is partly partitioned off within, from the main
cavity, leaving only a narrow elongate opening of communication. The base and sides of
the swollen portion of the tube are ornamented with numerous short tubuli. The interior
of the tube is strengthened on the side of the free valve by a slender central ridge
passing from the umbo of the fixed valve up the opposite side. The free valve is longer
than high, considerably inequilateral, thin, white, very compressed, broadly rounded
anteriorly, narrowed and produced behind. It is marked with rather coarse lines of
growth, and ornamented at the upper part with very fine granular lines which radiate
from the umbo not quite half-way across the valve. The beak is small, acute, slightly
raised above the hinge line, and situated considerably in advance of the centre. The
interior is glossy, somewhat wrinkled concentrically, and faintly substriated in the
opposite direction. The muscular scars and pallial sinus are very indistinct. Just
behind the apex of the umbo, and within the dorsal edge, there is a minute narrow
groove terminated behind by a small denticle which receives a minute ligament.

Length of free valve 12 mm., height 8; greatest width of tube 9, smallest width 4;
length of opening of communication between the narrow and swollen portions of the
tube 3, width 1.

Habitat. — Torres Strait, in 3 to 11 fathoms.

Family Myidje.

Subfamily Corbulin.e.

Corbitla, Bruguiere.

Corhida tunicata, Hinds.

Corhula tunicata, Hinds, Proc. Zool Soc. Lond., 1843, p. 55.

Corhula tunicata, Reeve, Conch. Icon., vol. ii. fig. 5.

Corhula tunicata, Tryon, Amer. Journ. Concli., vol iv. Appendix, p. 66.

Habitat. — -Port Jackson, Sydney, in 4 to 18 fathoms; off Amboina, in 15 to 25
fathoms; and Station 189, Arafura Sea, in 25 fathoms; green mud.

The specimens from the first two Stations are fine large shells agreeing in every
particular. The largest example is 28 mm. long, 19^ high, and 16 in diameter. Two
specimens from the Arafura Sea are somewhat abnormal both in form and sculpture,
occupying an intermediate position between this species and Corbida crai^m. The latter
species is more equivalve than Corbida tunicata, has the left valve sculptured throughout
like the right, which has a much smaller and less curved-over umbo than that of the

30 THE VOYAGE OF H.M.S. CHALLENGER.

present form. On the contrary, the left or smaller valve of Corhula tunicata has only
the earlier portion strongly ridged, the rest of the surface exhibiting only lines of growth
coated with a fibrous epidermis. The contrast between the two styles of ornamentation
is so marked that the valve presents the appearance of having the umbonal portion of a
differently sculptured species fixed on to its own smoother surface. The peculiarity, in
the two specimens from the Arafura Sea, consists in their having a much larger proportion
than usual of this valve strongly sculptured. In one there is scarcely any cessation of
the concentric ridging, whilst in the other it extends over about two thirds of the surface.
The ridges in this species are both more numerous and more rounded than in Corhula
crassa, which also presents another distinction in very adult examples that is never met
with in any specimens of any age of Corhula tunicata. I refer to the presence of fine
denticulation upon the dorsal and ventral margins of the left valve. A still closer
approach to the present species is met with in Corhula sulcata from West Africa.
Here is a species which not only has the same form, but offers scarcely any difference in
sculpture, and is mainly distinguished by a variation in colour.

Corhula crassa, Hinds, var.

Corhula crassa, Hinds, Proc. Zool. Soc. Lond., 1843, p. 53.
Corhula crassa, Keeve, Conch. Icon., vol. ii. figs. 8 a-c.

Habitat. — Torres Strait, in 3 to 11 fathoms (Challenger); Port Essington (J. B.
Jukes, Esq., in Brit. Mus.); Straits of Macassar, Malacca (Hinds) ; Bai.s, Island of
Negros, Philippines (Cuming).

The specimens from the above localities are somewhat different from the normal form
found at the Philippine Islands. In stoutness and outline they correspond very closely,
but are at once distinguished by the microscopic sculpture. The entire surface of the
valves is covered with a dense mass of minute circular granules, arranged more or less
regularly in closely packed radiating series. In the typical form the rows of granules,
which are of the same character, are much farther apart, and the apices of the valves
are smoother than in the variet)^ which has the concentric ribs developed somewhat
earlier. Beyond these differences there does not appear an}^ reason for separating these
two forms.

Corbula macgillivrayi, n. sp. (PI. X. figs. 8-8?>).

Testa magna, elongata, crassa, albida, paulo insequivalvis, valde insequilateralis, antice
rotundata, postice oblique truncata, ad extremitatem acute angulata, concentrice costata,
et radiatim minute granulato-striatn, costis ])one carinam ab umbone ad extremitatem

REPORT ON THE LAMELLIBRANCHIATA. 31

posticam decurrexitem tenuioribus, umbonesque versus subobsoletis. * Margo dorsi antifus
valde obli(|uus, subcoucavus, posticus minus declivis, fere rectilinearis, elongatus.
Margo ventris in medio late sinuatus, utrinque leviter excurvatus. Umbones parum
prominentes, albi vel rubeseentes, Isevigati. Pagina interna alba, plus minusve olivaceo-
fusco maculata, margine exterior! valvse sinistrse in testis adultis liic iUie minute denti-
oulato. Dens cardinis valvse dextrte erectus, aeutus.

This is a large species, very long, not particularly convex, whitish, only slightly
inequivalve, but very inequilateral. It is nearly twice as long as high, rounded at the
anterior end, obliquely and sharply truncated behind, terminating in an acute point.
The valves are moderately thick, and divided into two unequal parts l)y a sharp keel
ranning obliquely from the beaks to the hinder extremity. They also exhibit a shallow
depression down the middle, causing a sinus or incurvation in the ventral margin, which
otherwise is slightly arcuate. The dorsal slopes are unequal, the anterior being short, very
oblique and faintly concave, the posterior longer, less descending and nearly rectilinear.
The sculpture (consists of moderately strong, concentric ridges, which gradually increase
in thickness with, the growth of the shell, becoming behind the radiating carina slighter
than in front. In addition, the entire surface exhibits very numerous, excessively fine,
radiating lines, which are minutely granular, especially conspicuous in the grooves
between the costae. The beaks are only a little prominent, curve over towards the front,
and are almost smooth at the tips, which are usually white, but at times pinkish. The
single cardinal tooth of the right valve is erect, curved, and acute. The interior of the
valves may be either almost totally white, or more or less stained with olive-brown, or
occasionally with a pinkish tint. The margin of the left valve in old specimens is
more or less minutely denticulated aU round, a corresponding groove just ^\ithin the
circumference of the right valve being minutely pitted.

Length 26 mm., height 13, diameter 9.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; bottom, green mud.

Young shells of this species and of Corhula scaphoides are very much alike. The
latter are, however, flatter, more inequilateral, and have fewer and less elevated ridges,
which are much more obsolete behind the oblique keel.

This species is not likely to be mistaken for any other on account of its large size and
very elongate form. Corhula crassa offers some resemblance, but is proportionally
higher, more ec^uilateral, thicker, more coarsely ridged towards the umbones, more
suddenly contracted at the posterior or rostrated extremity, and has stronger hinge
characters.

32 THE VOYAGE OF H.M.S. CHALLENGER.

Corhula scaphoides, Hinds (PI. Ylll. figs. 3-3Z>).

Curhida scapJtoiden, IliiiJs, Proc. Zool. Soc. LoniL, 184.3, p. 5G.
Ciirhula scaphoides, Reeve, Concli. loon., vol. ii. tig. 2-t.

Habitat — Torres Strait, in 3 to 1 1 fathoms (Challenger) ; Singapore and Philippine
Islands (Hinds), Hong Kong Harbour (Bowring).

The specimens described by Hinds were apparently only the young of this species,
judging from a single right valve obtained by the Challenger. This valve bears a
considerable resemblance to the dee]) one of Corhula tunicata or Corhula sulcata, but
is much broader at the upper part, tlie young shell being much more elongate in this
species than in either of those mentioned. It is 25 mm. long, 17 high, and as
deep as that of Corhula tunicata. The young shell, about 13 mm. in length, forms
as it were an umbonal cap as in many species of this genus. From this point the
concentric ridges gradually thicken, and are more or less undulating. They are
attenuated anteriorly, and become more slender and closely packed at the carina, which
runs from the beak to the posterior extremity, which is much narrowed, and has a
pinched or nasute appearance. In young shells the surface is also ornamented with
numerous excessively fine radiating granular lirse, which are not, however, traceable in
the single adult valve, as the surface is too much worn. The hinder muscular scar is
situated on a shelf-like projection, this feature being also noticeable in the young shells.

In the British Museum there is a single adult specimen of this species from Hong-
Kong Harbour, presented by J. C. Bowi'ing, Esq. This is in perfect condition, but not
quite as large as the Challenger valve. There certainly is a very close relationship
between this species and Corhula tunicata, the main distinction consisting in the much
longer umbonal portion of the valves in the present form. Both have exactly the same
kind of radiating series of minute circular granules, the epidermis covering the lower half
of the left valve is similar in both forms, and the muscular impressions are not very
dissinailar, although in Corhula scaphoides the posterior stands out rather more than
that of Corhula tunicata. Both have exactly the same stout, curved, and acute
cardinal tooth in the deep valve, and their external ribbing is also similar.

Corhula modesta, Hinds.

Corhida modesta, Hinds, Proc. Zool. Soc. Lond., 1843, p. .57.
Corhida modesta, Reeve, Concli. Icon., vol. ii. fig. 14.
Corhvla modesta. Smith, Proc. Zool. Soc. Lond., 1871, p. 728.

Hahitat. — Amboina, in 15 to 20 fathoms; also Station 172, off Nukalofa, Tongatabu,
in 18 fathoms (Challenger); Philippine Islands and Malacca (Hinds); ^^^lydah, West
Africa (Knocker).

REPORT ON THE LAMELLIBRANCHIATA. 33

Occasion lias already becu taken to remark upuu the great similarity existing between
two species of this genus, the one {Curhula siiJcata) from the shores of Western Africa,
the other {Corhula tunicoAa) from Amboina, the Philippines, North and East Australia.
In the present instance I have to repeat tlie record of the existence of the very same
shell from all these localities, with the exception of East Australia. A single example
dredged by Captain Knocker, R.N., at Whydah, on the Dahomey shore, was referred to
this species by myself in 1871. I have again most carefully examined it, and see no reason
for altering that location. The apices of the umbones are of the same smooth porcel-
lanous whiteness, bordered in front with a pinkish stain as in eastern specimens, the
concentric ribbing is identical, the colour of the interior the same, and the hinge and
muscular scars correspond in every respect.

If there were more specimens for examination, it is possible some distinguishing
feature might present itself, but at present I feel certain of the identity of these shells
from such widely remote and distinct zoological provinces.

Corhula pMlippii, n. sp. (PI. VIII. figs. 4-46).

Testa parva, valde insequivalvis, insequilateralis, triangulariter ovata, alba, valva
sinistra epidermide fibrosa prope marginem induta. Valvse crassiusculse, diverse sculptae.
Valva dextra convexa, postice breviter rostrata, ad extremitatem truncata, obtuse
bicarinata, costellis rotundatis, crassiusculis, concentricis, prope carinam anteriorem fere
evanidis, instructa. Valva sinistra longe minor, incrementi lineis striata, liris paucis
radiantibus ornata. Umbones valde prominentes, involuti, nivei, l?evigati. Linea
cardinis utrinque declivis, rectiuscula, fusco tincta.

This compact little species is very inequivalve, rather convex, somewhat inequilateral,
triangularly ovate with the umbones well raised. The anterior end is sharply rounded, the
posterior subrostrate, shortly and slightly obliquely truncate, the lower margin being well
curved in front and at the middle, and very faintly incurved behind near the lower angle
of the rostrum. It is w^hite with the exception of a slight tinge of brown upon the hinge-
margin, chiefly behind the beaks, and the left valve is clothed more or less, principally
towards the lower outline, with a yellowish fibrous epidermis. The right valve, which is
far the larger, has an obtuse ridge running from the apex obliquely to the lower end of
the hinder truncation, marking off" a definite and somewhat concave posterior area, and
within this, close to the dorsal margin, it has a second less noticeable rounded carina.
Its sculpture consists of rounded concentric ridges which gradually tliicken as the shell
increases. They are numerous, broader than the intervening grooves, attenuated (in
some instances obsolete) anteriorly, and become mere strise between the radiating cariu;e
behind. The left valve merely exhibits fine concentric lines of growth and a few (about

(ZOOL. CHALL. EXP. PART .XXXV. — 1885.) Mm 5

34 THE VOYAGE OF H.M.S. CHALLENGER.

eight) inequidistant radiating ridges, wliicli do not, however, extend quite up to the beaks.
These in both valves are smooth, rather glossy, almost snow-white, and well rolled in
and forward. The right valve has a simple strong erect cardinal tooth immediately beneath
the beak, which fits into a corresponding pit in the left valve, behind which is a stout
process or denticle supporting the ligament. The interior is more or less stained with
brown, the anterior scar elongate, the posterior rounder, and the pallial line faintly sinuated.

Length 6 mm., height 5 J, diameter 3f.

Habitat. — Station 33, off Bermuda, in 435 fathoms ; coral mud ; (Challenger) ;
Hayti (Coll. Cuming in British Museum).

This interesting little species does not appear to agree with any of the numerous
forms already described from the West Indian region. In the inequality of the valves it
resembles Corbula ojyerculata, Philippi, from St. Thomas Island, but differs from that
species in size, form, the absence of the double keel in the right valve, and in the difiierent
sculpture of the left.

Corbula monilis, Hinds.

Corbula monilis, Hinds, Proc. Zool. Soc. Lond., 1843, p. 58.
uorhula monilis, Eeeve, Conch. Icon., vol. ii. pi. v. fig. 35.

Testa minuta, alba, globosa, paulo inaequdateralis, antice rotundata, postice leviter
producta, plus minusve truncata. Margo dorsi utrinque valde declivis, leviter arcuatus,
ventralis late curvatus, postice paululum sinuatus. Valvse mediocriter tenues, valde
insequales, liris concentricis gracilibus instructse. Umbones magni, inflati, prominentes,
antrorsum curvati.

This species, several specimens of which were obtained, all of the same minute
dimensions, is somewhat inequilateral, considerably inflated, moderately thick for so smaU
a shell, white, inequivalve, and marked with fine concentric lirse. . The dorsal slopes are
somewhat curved and very oblique, the ventral outline being slightly arcuate, and a little
sinuated posteriorly. The anterior end is sharply rounded, the hinder extremity being
a. little produced and somewhat truncated. The umbones are rather large, elevated
above the hinge line, and terminate in a minute glossy tip curved over towards the
front. The right valve has a single erect, strong tooth, immediately beneath the apex
of the beak, and in the left there is a triangular pit for its reception.

Length 2 mm., height If, diameter 1^.

Habitat. — Stations 186, 187, and 188, all in Torres Strait, North Australia, in 3 to
28 fathoms.

This minute form was originally described from specimens collected at the island of
Luzon. The largest of these Philippine examples is 2f mm. long, 2^ high, and 2 in
diameter.

REPORT ON THE LAMELLIBRANCHIATA.

NecBra, Gray.

The number of species in this genus has very considerably increased of recent years,
and although they have been subdivided to some extent by A. Adams/ and arranged into
sections by Dr Gwyn Jeffreys,* some further revision ajjpears to be still requisite.
Adams' arrangement is based partly on hinge-characters and partly on external features,
that of Jeflreys being founded solely on differences of sculpture, the result being that
shells are found in the same sections with others, the hinges of which are very different,
e.g., Necera teres, Necera semistrigosa, Necera injiata, &c.

Having examined a large number of species, I have found certain differences in their
hinges which may form the basis of a rearrangement, in submitting which, however, I at
present refrain from naming the sections in which I have grouped the species, awaiting
still further material, so that their validity and usefulness may be tested. Those species
whose names are marked with an asterisk (*) have been located from description only,
and not from personal examination.

Section A. (Necera proper).

Teeth. — A single more or less elongate lateral tooth on the posterior side 'in the right
valve, none in the left.

Cartilage. — More or less obliquely inclined posteriorly.
Surface. — Concentrically striate, lamellated, or costate.

Necera cuspidata, Olivi.
rostrata, Spengier.
obesa, Loveu.
suhtorta, Sars.
hindsiana, A. Adams.
rosea, Hinds.
circinata, Jeffreys.
aiocarinata, kerg uelenensis,

plateiisis, angasi, meridi-

onalis, consociata, azorica,

capensis, patago7iica,wolla-

stonii, all n. sp.
chinensis, Gray.
latisidcata, Tenison-Woods.
elegans, Hinds.

Necera arcuata, Dall (?)

Necera gracilis, Jeflfreys.

bicarinata, Jeffreys.
depressa, Jeffreys.
limatula, Dall (?) = con-

tracta, Jeffreys.
ruginosa, Jeffreys.
truncata, Jeffreys.'
arctica, Sars.'"'
glacialis, Sars.*
jugosa. Wood.*
papyria, Jeffreys.*
exigua, Jeffreys.*
nobilis, A. Adams.*
nasiita, A. Adams.*
trailli, Hutton.*

* Ann. and Mag. Nat. Hist., 1864, vol. xiii. p. 206.
^ Left valve only examineil.

2 Proc. Zool. Soc. Land., 1881, p. S.^B.

36 THE VOYAGE OF H.M.S. CHALLENGER.

Section B. — Subgenus Cardiomija , A. kA-M\\s = Spathophora, Jeffreys.

Teeth. — Same as in {Necera proper) Section A.
Cartilage. — Less oblique than in the above.
Surface. — Eadiately costate or Urate.

NecBva goukUana, Hinds.
costeUata, Deshayes.
fallax, n. sp.
pectinata, Carpenter.
costata, Sowerby.

Section O.

Necera concinna. Hinds.
striata, Jeffreys.
curta, Jeffreys.
multicostata, Verrill and
Smith.*

Teeth of right valve, Cartilage-Pit, and Sculpture, the same as in Section A, but a
small erect posterior lateral tooth is present in the left valve.

Necera pulchella, H. Adams.

Section D.

Teeth. — One small lateral tooth on each side near the beak in both valves (the
anterior in the left being feeble).

Cartilage and Surface as in A and B.

Necera singaporensis, Hinds.

Section E.

Teeth. — A short lateral tooth on each side in the right valve, with coiresjjonding pits
in the hinge-margin of the left, more conspicuous on the anterior side than behind.
Cartilage. — Obliquely inclined towards the posterior end.
Surface. — Concentrically striated.

Necera teres, Jeffreys.

Section F.

Teeth. — A short erect lateral tooth on each side, and a small dentiform projection of
the hinge-margin in front of the apex in the right valve, and a single tubercular denticle
in front of the apex (but no laterals) in the left.

REPOET ON THE LAMELLIBRANCHIATA.

Cartilage. — Posteriorly inclined, not in a pit or process, but attached to the valves.
Surface. — Concentrically striate. •

Necera hrazieri, n. sp.

Section Gt. — Subgenus Rhinomya, A. Adams.

Teeth. — One lateral tooth on each side in the right valve, none in the left.
Cartilage. — Internal, attached to the valve under the beaks.
Surface. — Concentrically striate.

Necera rugata, A. Adams.'"'

pliilippinensis, A. Adams
{nee Hinds).

Necera notabilis, Jeffreys.*

lamellifera, Dall = semi-
strigosa, Jeffreys.

Section H.

Teeth. — One small conical tooth in front of the umbo in the right valve, none in left :
no laterals in either.

Cartilage. — Narrow, vmder apex, parallel with margin.
Surface. — Concentrically striate.

Necera phiJippinensis, Hinds.

Section I.

Teeth. — A single denticle in both valves in front of the beaks ; no laterals.
Cartilage. — Elongate, narrow, subparallel with the dorsal edge.
Surface. — Concentrically plicate.

Necera abbreviata, Forbes.

Section J.

Teeth. — One small thickish tooth on each side in the right valve, and a similar one
in the left, in front only.

Cartilage. — Very small, central.
Surface. — Finely ridged.

Necera culuncct, Gould.

38 THE VOYAGE OF H.M.S. CHALLENGER.

Section K.

Teeth.-;— A. single acute denticle in the right valve in front of the cartilage-pit, and a
long shelf-like process parallel with the posterior dorsal margin in each valve.
Cartilage-Pit. — Small, central or oblique.
Surface. — Concentrically striate.

NecBra claviculata, Dall. | Necera injlata, Jeffreys.

NeoBra congenita, n. sp.

Section L.

Teeth. — None in either valve.

Cartilage. — Small, oblong, attached to a thin shelly process and directed posteriorly.

Surface. — Concentrically lamellar or striated.

Necera angularis, Jeffreys. | Necsra sulcifera, Jeffreys.

Section M.

Teeth. — None in either valve.
Cartilage. — Short, anteriorly inclined.
Surface. — Eadiately costellate.

Necera fragilissima, n. sp.

The subjoined Table will show at a glance the considerable difference in the structure
of the hinges of the subgenera or sections. In some cases the teeth appear to be
the same, as in A and B, and L and M, but in these instances there are other
differences in the cartilage or sculpture which constitute the chief points of distinction.

REPORT ON THE LAMELLIBRANCHIATA.

Right Valve.

Left Valve.

Sections.

Anterior
cardinal.

Anterior
lateral.

Posterior
lateral.

Anterior
cardinal.

Anterior
lateral.

Posterior
lateral.

The hinges of the following species are unknown to me, and therefore I have been
unable to locate them in any of the proposed sections : —

Necera crassa, Monterosato.

tasraanica, Tenison- Woods.
pura, Angas.
granulata, Dall.

Nemra jeffreysi, Dall.
casta. Hinds.
didyma, Hinds.
trigona, Hinds.

Section A.

Necera patagonica, n. sp. (PI. VHI. figs. 5-55).

Testa NewrcB wollastonii similis, sed crassior, paulo in?equilateralis, rostro postico
longiori et graciliori desinita.

' Hinge margin with pits for reception of the teeth of the right valve.

2 These are hardly teeth, but rather elongate, shelf-like processes -nithin the hinge-margin.

40 THE VOYAGE OF H.M.S. CHALLENGER.

Length 29 mm., height 14, diameter 12.

Habitat. — Station 305, west coast of Patagonia, in 165 fathoms ; l)lue mud.

Both this species and Neceixt woUastonii may eventually prove to be large varieties
of Ne(Bra rostrata, Spengler, being similarly sculptured. Still there is a considerable
difference in form. The single left valve from the above locality has the apex of the
umbo (viewing it from within) situated 13 mm. from the anterior end, or only one
and a half in advance of the centre. From this it will be seen that it is more equilateral
than Necera rostrata, but less so than Necera woUastonii.

NecBra ivollastonii, n. sp. (PI. X. figs. (j-Qh).

Testa magna, tenuis, alba, hand nitida, globosa, ovata, postice louge rostrata, incre-
ment! lineis tenuibus striata. Margo dorsi auticus oblique arcuatus, posticus minus
declivis, levissime concavus. Ventris margo antice et inferne late arcuatus, ad rostrum
late sinuatus. Rostrum elongatum, marginibi;s subparallelis, carina obliqua leviter
curvata dimidiatum, ad extremitatem posticam subrecte truncatum. Umbones magui,
involuti, ad apicem sublsevigati, centrales. Pagina interna nitens, plus minusve radiatim
substriata. Linea cardinis tenuis, subreflexa, sub umbone valvae sinistra^ loculo
ligamentali parvo obliquo instructa.

This is a large thin shell, much inflated, ovate, and terminated behind in a long beak.
It is white, with scarcely any gloss upon the surface, and sculptured with fine striae of
growth only. The hinder dorsal margin is slightly oblique and the least concave, the
anterior being arcuate and more sloping, but this depends u^ion the position in which the
shell is regarded. The anterior end is semicircularly rounded, the ventral outline more
broadly curved and widely sinuated at the commencement of the rostrum. This has the
upper and inferior margins almost parallel, the extremity nearly abruptly truncate, and is
obliquely bisected by a slight radiating ridge. The umbones are considerabl}^ elevated,
exactly central, smoothish, and incurved at the tips. The hinge-line in the left valve is
thin, a little expanded upwards on both sides of the umbo, immediately beneath which is
a very small ligamental pit directed obliquely towards the hinder end. The interior is
glossy,, and exhibits a distinct substriation about the central parts. The posterior
muscular scar is elongate, and situated under the dorsal line not quite half-way from the
umbo to the end of the rostrum.

Length 26 mm., height 14^, presumed diameter of the complete shell 12.

Habitat. — Station 73, a little west of the Azores, in 1000 fathoms ; Pteropod ooze.

I have named this species in remembrance of the late T. V. Wollaston, who contri-
buted so much to our knowledge of the fauna of the islands of the Atlantic. It is a

REPORT ON THE LAMELLIBRANCHIATA. 41

larger shell than Necera rostrata, Spengler, although very similarly sculptured, and
terminates in a much shorter posterior rostrum.

Neceixi consociata, n. sp. (PI. IX. figs. 7~7b).

Testa parva, tenuis, pellucida, globosa, postice subito rostrata ; rostrum breve,
truncatum, increment! lineis subvalidis sculptum, carina obliqua distincta dimidiatum.
Valvse antice rotundatse, inferne late arcuatje, postice prope carinam subprofunde sinuatae,
lamellis brevibus paucis (circa decern) ornatse. Umbones Iseves, leviter prominentes,
antemediani, fere in ^ longitudinis collocati. Cardo in valva sinistra edentulus, in
dextra ? Fossa ligament! linearis, margine dorsali parallela, baud intus projecta.

This species must approach very closely Necera lamelUfera of Dall, and may indeed
prove eventually to be the young state or a variety of it. It may, however, be at once
distinguished from that species, which is only known to me by description, by the
distinct keel, which, starting from the lower corner of the rostrum, curves up obliquely
towards, but does not extend quite to, the umbones. The latter, too, are apparently
placed more forward, being just a shade more than one-third of the total length from the
anterior end, whilst in Necera lamelUfera they appear to be very little in advance of the
centre. Both species are similarly sculptured with fine concentric lamellae, and there is
probably not much difference in the ligamentary fossette. The freshest valve procured is
thin, glassy, and subtransparent, and, on examination under the microscope, presents a
minutely punctate surface towards the umbo, both within and without.

Length 4^ mm., height 3, approximate diameter 2^^.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms, Pteropod
ooze; and Station 33, off Bermuda, in 435 fathoms, coral mud.

Necera azorica, n. sp. (PI. X. figs. 7-7h).

Testa tenuis, inajquilateralis, ovata, supernc recta, vix rostrata, mediocriter couvexa,
hand nitida, rugis concentricis miuutis irregularibus postice subito obliquis ornata.
Margo dorsi fere rectus, antice leviter curvatus. Latus anticum breve, rotundatum,
posticum longius, rostro brevissimo, impressione baud profundo ab umbone radiant!
signato, terminatum. Ventris margo late arcuatus, postice ad impressionem levissime
sinuatum. Umbones parvi, parum prominentes, nucleo uitente obtuso instructi, ante
medium collocati. Ligamentum minutum, obliquum.

Only a single left valve is at present known of this species. It is small, thin,
rather inequilateral, irregularly ovate, having the upper margin nearly straight and the
posterior end only a very little beaked. It is semitransparent-white, moderately convex,

(ZOOL. CHALL. EXP. PART XXXV. — 1885.) Mm 6

42 THE VOYAGE OF H.M.S. CHALLENGER.

and sculptured with numerous concentric, very fine, and irregular wrinkles, which, in a
depression that marks off the slight rostrum, turn suddenly to the right in an
oblique direction. The front and lower outlines are regularly curved, the latter, how-
ever, exhibiting a slight sinuation at the radiating depression. The fi'ont portion of the
dorsal edge is very short, feebly excurved, the posterior, on the contrary, being long
and almost rectilinear, or very slightly concave. The umbo is small, but little raised,
situated considerably in front of the middle, and terminates in a minute glossy vitreous
obtuse boss. The hinge-plate is thin, bearing immediately below the beak a minute
oblique ligamental jiit. The interior is glossy, with only faint muscular scars.

Length 4|- mm., height 3^, presumed diameter of a complete specimen 2|.

Habitat.- — Station 78, east of the Azores, in 1000 fathoms; volcanic mud.

This species is remarkable for the smallness of the rostrum and the peculiar wrinkled
character of the concentric sculpture.

NecBra circinata, Jeffreys (PL X. figs. 4-46).

Necera circinata, Jeffreys, Ann. and Mag. Nat. Hist., 1876, ser. 4, vol xviii. p. 497.
Ncara circinata, Jeffreys, Proc. Zool. Soc. Lond., 1881, p. 942, pL Ixxi. fig. 6.

Habitat. — Station 73, west of the Azores, in 1000 fathoms, volcanic mud; and at
Station 85, Canary Islands, in 1125 fathoms, volcanic mud (Challenger). Other localities
which I give on the authority of Dr. Jeffreys, all north Atlantic, lat. 56° 11' N., long.
37° 41' W., in 1450 fathoms ; off the west of Ireland, lat. .56° 7' N., long. 14° 19' W., in
630 fathoms ; west of Portugal, lat. 39° 55' N., long. 9° 56' W., in 994 fathoms ; Bay of
Biscay.

The figure in the Proc. Zool. Soc. gives a fair idea of the Challenger specimens, but
certainly exhibits a too sudden contraction of the rostrum, consequently the sinus in the
ventral outline becomes too deep. The upper angle is not sufficiently sharp, and the
position of the umbones is too forward, being in the shells before me (when viewed in the
same position as the figure) exactly midway between the extremities. If these specimens
had not been examined by Dr. Gwyn Jeffreys, and pronounced to belong to this species,
I should almost have felt warranted in separating them specifically, for besides the
differences already alluded to, there are other points in which they do not agree with the
description in the Annals. There no mention is made of the position of the beaks, the
shell is described as " rather solid," and as having " about twenty-five fine concentric and
equidistant lamellar ridges or strise in the middle of the shell, which become compressed
in front and disappear at the sides." The Challenger shells certainly are not " rather
solid," but may be so in comparison with certain other species, and the concentric
lamellae, in a specimen of the same size as that figured by Jeffreys, are considerably more
numerous, there being as many as forty. Another feature which is not referred to by

REPORT ON THE LAMELLIBRANCHIATA. 43

Jeffreys is the presence of a rather strongly marked impressed ray within the valves,
extending obliquely from beneath the umboues down the anterior side.

Necera obesa, Loven.

I^ecB-ra obesa, Lovdn, Ofversigt k. Vetensk.-Akad. Forhandl., 1840, p. 202, Xo. 326.
Necera obesa, Sars, Moll. Arct. Xorv., p. 86, pi. vi. figs. 4a-c.
Netera pelliicida, Stimpson, Invert. Grand Manan, p. 21, pi. i. fig. 13.

Habitat. — Station 78, off San Miguel, Azores, at a depth of 1000 fathoms, volcanic
mud (Challenger) ; West Norway, in 40 to 650 fathoms (Sars) ; Eastern North America
(Verrill); off* Long Island, in 40 fathoms (Stimpson). Atlantic Ocean, lat. 47° 38' N.,
long. 12° 8' W., 2435 fathoms (Jeffreys, "Porcupine" Exped., 1869); also Stations 1
and 3 of the 1870 Expedition; lat. 48° 38' N., long. 10° 15' AV., 567 fathoms; lat.
48° 31' N., long. 10° 3' W., 690 fathoms.

A single small right valve from the above Station, only 5 mm. in length, is all that
was obtained of this species. In form and sculpture it corresponds precisely with the
above quoted figure of Sars.

Necsra meridionalis, n. sp. (PL IX. figs. 6-66).

Testa fragilis, tenuissima, alba, concentrice subrugose striata, epidermide tenui induta,
paulo in^quilateralis, alta, antice late rotundata, postice breviter lateque rostrata. Valvae
fere asquales, subtumidaa, sinistra sulco hand profundo ab umbone radianti prope
extremitatem posticam sculpta. Margo dorsi anticus brevis, primo parum obliquus,
aliquanto arcuatus, posticus horizontalis, fere rectus ; margo inferior late curvatus, antice
subito ascendens, posterius oblique surrectus, leviter sinuatus. Fossa ligamenti minima,
obliqua. Pagina interna nitida, radiatim substriata, dense minuteque granulata.

This is a broadly rostrate species, excessively thin, high, tumid, broadly rounded in
front and somewhat obtusely wedge-shaped behind. It is white, covered with a very
thin epidermis, and exhibits distinct lines of growth and a shallow groove in the left valve,
radiating from the apex to the margin near the hinder extremity, there being only the
faintest indication of a similar furrow in the opposite valve. The dorsal margins are
very unequal. The anterior is short, faintly excurved at first, then arcuate and suddenly
descending, forming with the upcurved lower margin a broadly rounded extremity. The
posterior margin is much longer, almost horizontal and straight, and the ventral outline
is widely arcuate, except behind, where it rises with a faint incurvation in an oblique
dii-ection. The umbones are rather large and tumid. The cartilage-pit is very small,
inclined towards the posterior end, and the lateral lamellar tooth of the right valve is
elongate. The internal surface of the valves is somewhat 2;lossr, exhibits a sort of close
radiating substriation, and, under the microscope, appears to be minutely granular.

44 THE VOYAGE OF H.M.S. CHALLENGER.

Length 17^ mm., height 11, diameter 7^.

Habitat. — Station 157, in the Southern Ocean south-west of Australia, at a dejith of
1950 fathoms; Diatom ooze.

This species is peculiarly broadly beaked, rather swollen, and excessively thin. Since
this description was written the uni<|ue specimen has been accidentally smashed, only the
crushed fragments remaining. It is, however, probably capable of partial repair, and it
is fortunate that it had already left the artist's hands before it was destroyed.

Necera Jilocarinata, n. sp. (PI. X. figs. 5-56).

Testa elongata, antice globosa, ]50stice subanguste rostrata, tenuissima, albida, hand
nitida, lineis regularibus elevatis concentricis rostrum versus corrugatis sculpta. Margo
dorsi anticus declivis, parum arcuatus, posticus paulo concavus, obliquus ; margo inferior
curvatus, postice ad rostrum leviter sinuatus. Rostrum rotunde truncatum, carina
filiformi radianti arcuata dimidiatum, et carina alia prope marginem dorsalem instructum,
striis transversis corrugatus liueisque paucis radiantibus inconspicuis insculptum.
Umbones parvi, parum producti, paulo antemediani. Valva sinistra omnino edentula,
dextra dente unico laterali tenui vitrinque instructa. Ligamentum parvum, obliquum.

This is a very thin species, rather globular, with the exception of the posterior
rostrated portion. It is somewhat inequilateral, whitish, wdthout gloss, sculptured with
very fine and rather regular concentric elevated lines which become more or less indistinct
and wrinkled in the faint dt'pression marking ofl' the rostrum. The front dorsal margin is
very faintly excurvcd and rather sloping, the hinder, on the contrary, being a little
concave, longer, and also oblique. The ventral is broadly excurved in front and at the
middle, but has a shallow siuuatiou at the depression towards the commencement of the
rostrum. This is roundly truncated at the end, and is divided by a distinct, slightly
arcuate, thread-like ridge, which radiates from the beak to the lower extremity. It also
exhibits a similar but rather more slender keel close under the upper margin. It is
sculptured by wrinkled cross hnes of gro"wi;h, and bears in addition a few inconspicuous
radiating lines. The umbones are not much elevated above the hinge-line, small,
inclined towards the front, glossy at the tip, and situated rather in advance of the centre.
The left valve is altogether toothless. The right has a single lamellar tooth on each
side, the anterior being a trifle nearer the apex than the posterior, which, however, is the
larger of the two. The ligament is small and inclined posteriorly. The interior is
shining and concentrically streaked with opaque white upon a subpellucid white ground.

Length 9^- mm., height 5f, diameter 5.

Ilahitat. — Station 98, off West Africa, in 1750 fathoms; Globigerina ooze.

EEPORT ON THE LAMELLIBRANCHIATA. 45

Necera capensis, n. sp. {PI. IX. figs. 5-56).

Testa tenuis, ovato-rostrata, iiifequilateralis, albida, epidermide tenuissima induta,
iiicrementi lineis striata, latere uutico subacute rotundato, postico anguste rostrato,
rostro circiter ^ longitudinis sequante. Margo dorsi anticus valde declivis, leviter
convexus, posticus longior, minus obliquus, concavus. Ventris margo regulariter
arcuatus, postice ad rostrum sinuatus. Umbones pauIo postmediani, leviter supra
marginera elevati.

Like most species of Necera this is very thin and fragile. It has a rather long beak
behind, is somewhat acutely rounded in front, rather angular at the apex, and well
curved below. It is inequilateral owing to the length of the rostrate end, whitish, and
covered, more or less, with a thin but rougliish epidermis, which is less worn off the beak
than elsewhere. The front dorsal outline is slightly convex and considerably sloping, the
posterior being somewhat longer, less oblique, and gently concave. The sculpture
consists of fine concentric lines of growth, most conspicuous upon the beaks. The
<-artilage-pit is small, the lamellar lateral tooth of the right valve moderately long and
erect, and the scars and pallial line very indistinct.

Length 15 mm., height 8, diameter 5.

Habitat. — Station 142, off the Cape of Good Hope, at a depth of 150 fathoms ; green
sand.

This, like several other species of the genus, is principally distinguished by its shape,
there being little of importance as regards sculpture, epidermis, and hinge to separate
it from certain allied forms. It differs from Netera rostrata, Spengler, in possessing a
shorter beak, and the ventral margin in front of the rostrum is longer and less arcuate.
In outline it more closely resembles Nccera hindsiana, A. Adams, from Japan, but differs
from it in having finer concentric sculpture and a more acute anterior end.

Necera j^lciten.sis, n. sp. (PI. IX. figs. 4-46).

Testa tenuis, albida, elongata, antice acute rotundata, postice sublonge rostrata,
mediocriter globosa, incrementi lineis striata, hand nitida. Margo dorsi anticus primo
rectiusculus, deinde obliquus, parum arcuatus, posticus elongatus, paulo declivis, subrecti-
linearis vel leviter concavus. Margo inferior late arcuatus, postice sub rostro sensim
sinuatus. Umbones leviusculi parum prominentes, paulo ante medium collocati.
Rostrum impressione radianti definitum, subabrupte truncatum. Valva dextra dente
laterali lamcUiforuie postico instructa. Fossa ligamenti valvte sinistra^ minuta, paulo
obliqua. Linea cardinis ante umbones leviter expansa.

This species is very thin, ovate-rostrate, moderately convex, sharply rounded in front,
and ends behind in a rather long but not very slender beak. It is white, without

46 THE VOYAGE OF H.M.S. CHALLENGER.

lustre, and sculptured with fine lines of growth. The valves exhibit a broad shallow
depression, radiating from the umboues and marking ofi' the rostrum. This is rather
abruptly truncate at the end, and faintly ridged from the beak to the lower corner, with
the lines of growth rather strongly developed. In the left valve there is a second slight
ridge, very close to the upper margin, marking off a linear dorsal area. The front dorsal
margin rises a little, close to the umbo, then descends obliquely with only a very slight
curve. The j^osterior margin is longer, slopes but very little, and is the least concave.
The ventral outline forms under the main portion of the shell a regular broad curve, but
at the termination of the radiating depression is gently sinuated. The umbones are only
a little elevated, and somewhat in advance of the centre. The left valve is toothless, but
possesses a minute and slightly oblique cartilage-pit just under the apex. The right valve
has a single slender elongate lamellar tooth on the posterior side, and the hinge-line in both
valves in front is a little expanded. The muscular impressions are very feebly indicated.

Length 13 mm., height 7, diameter 5.

Habitat. — Station 320, otf the mouth of the Eio de la Plata, in 600 fathoms ; green
sand.

In form this species resembles to some extent Necera ohesa, Loven, and Necera
Umatilla, Dall. It is less convex than the former, is more sharply rounded in front, and
has less prominent umbones, the latter being more strongly sculptured.

Necera herguelenensis, n. sp. (PI. XXIV. tigs. 8-8/*).

Testa parva, subglobosa, postice bi'eviter rostrata, concentrice lirata, liris tenuibus
valde elevatis, sujara rostrum flexuosis, ad liram obliquam medianam obsoletis. Margo
dorsi anticus rectiusculus, declivis, posticus paulo concavus, minus obliquus. Margo
inferior antice et in medio late curvatus, sub rostro distincte sinuatus. Umbones parvi,
circa in medio, ad cacumina leves. Valva dextra dente unico valido submarginali pone
umbonem munita, valva sinistra contra edentida.

This little shell is rather globose, nearly equilateral, rounded in front, much contracted
and beaked behind. It is white, and ornamented with about twenty, fine, much elevated,
concentric, lamelliform Yivsd, which are attenuated and flexuous in a depression or con-
striction marking off the rostrate end, and almost terminate at a slight keel which runs
from the umbones to the lower corner of the curved truncate beak. Above this carina
there is a second finer one, but nearer to the dorsal edge. The front dorsal margin is
somewhat oblique, but not much curved, the posterior being rather concave. The ventral
outline is distinctly sinuate under the rostrate end, and greatly arcuate at the lower part
and in front. The umbones are small, nearly central, and smooth at the tips. The hinge
is composed of a single strongish tooth in the right valve, situated within the dorsal
margin just behind the umbo.

JIEPORT ON THE LAMELLIBKANCHIATA. 47

Length 4 J mm., height 3, dinmetcr 2|.

Habitat. — Off Christmas Harbour, Kerguclen IsLand, in 120 fathoms.

A pretty little species, remarkable for its elevated thin lamelliform lirse.

Necera angasi, n. sp. (PI. IX. figs. 2-26).

Testa NecBrcB rostratce similis, sed margine dorsi antico magis obliquo, rectiusculo,
margine ventrali postice minus subito contracto, denteque laterali posteriori valv£e dextrse
graciliori.

Length 9^ mm., height 5, diameter 3^.

Habitat. — Station 164b, off the coast of New South Wales, in 410 fathoms; green mud.

This species is so very like Nea'ra rostrata of Spengler, that to give a detailed
description of it becomes unnecessary. It docs, however, differ a little in form, the hinder
dorsal slopes being almost rectilinear and a trifle more oblicpie. There is a difference
also in the lower margin, the contraction at the commencement of the rostrum being less
sudden, and the anterior end is rather more acute. The sculpture in both forms is of the
same character, although that in the Australian shell is perhaps somewhat more delicate.
The present species has also a smaller and more slender hinder lateral tooth in the right
valve. I have much pleasure in naming this species after my friend G. F. Angas, Esq.,
who lias written several important papers on the Molluscan fauna of Australia.

Since the above description was written the only specimen obtained has been
accidentally smashed, but fortunately after leaving the artist's hands.

Necera elegans, Hinds.

Nerera elegans, Hinds, Proc. Zool. Soc. Loud., 1843, p. 7G.

Necera elegans, A. Adams, Ann. and Mag. Xat. Hist., 1864, vol. xiii. p. 206.

Necera moluceana, Adams and Eeeve, Zool. Voy. Samarang, ]\Iollusca, p. 84, pi. xxiii. fig. 4.

Habitat. — Station 189, Arafura Sea, south-west of New Guinea, in 25 fathoms, green
mud (Challenger) ; New Guinea, China Sea, and Singapore, on a muddy floor, in from
7 to 18 fathoms (Hinds); Molucca Islands, Gillolo (Adams and Reeve); Mine Sima,
Japan, in 63 fathoms (A. Adams).

I fuUy concur Tvith Adams and Tryon ' in considering the Necera, rtwluccana synony-
mous with this species. It is a form easily recognised by the peculiarity of its oblique
sculpture. It is rather convex, thin, not glossy, covered more or less with a very thin
pale epidermis, sharply rounded in front, contracted and narrowly rostrate behind. The
ventral outline is regularly widely arcuate under the main portion of the shell, with a
sudden sinuation at the commencement at the beak. The anterior dorsal margin is

' Amir. Journ. Conch., vol. iv., Appendi.x, p. 97.

48 THE VOYAGE OF H.M.S. CHALLENGER.

faintly curved and rather oblique, the posterior, which is somewhat longer, being, on the
contrary, considerably concave. The valves are all but equal, and sculptured with
numerous oblique, wavy, slender ridges, which almost disappear in front, leaving a com-
paratively smooth lunular space, and vanish posteriorly at a fine radiating keel which
bisects the rostrum. The latter bears nearer the dorsal edge a second carina, which, being
slightly curved, marks oS' a smooth narrow dorsal area, the space between the ridges
being, on the contrary, marked with rather rough transverse lines of growth, these on the
rest of the valve, being concentric, cut across the oblique riblets. The cartilage-process
is small, short, and inclined slightly posteriorly. The right valve has a thin elongate
hinder lateral tooth.

NecBra sp.

Habitat. — Station 23, ofi' Sombrero Island, West Indies, iu 450 fathoms ; Pteropod
ooze.

Only the umbonal portion of a right valve was obtained, wliicli, on account of its
large size, may be wortli recording. It indicates a species of as large size as Netera
chinensis, Gray, and equally solid. It evidently has a long slender rostrum, and is
sculptured like Necera rostrata, Spengler. It has a trigonal cartilage-pit having the
lower margin rounded and placed almost perpendicularly under the tip of the beak.
There is a very strong short erect hinder lateral tooth, immediately beneath which is a
very deep muscular scar.

NecBra sp.

Habitat. — Station 24, oil' Culebra Island, West Indies, in 390 fathoms; Pteropod ooze.

A single left valve from the above Station is apparently distinct from all the
numerous known species of this genus. It is very thin, probably young, pellucid,
moderately convex, shortly rostrate, glossy, and sculptured with fine lines of growth
towards the lower outline. The hinge-line is almost horizontal, very slightly excurved
anteriorly, and very feebly concave behind. The anterior end is broadly rounded, and
joins the dorsal margin with a rounded angle. The lower outline is well curved, rising
considerably at the posterior end, Avhere it is also shallowly sinuated. The Ijeak,
di\ided by a slight ridge radiating from the umbo to the lower corner, exhibits one or two
other very faint raised radiating lines, and is rather abruptly truncated. The umbo is
small, .shining, only a little elevated, and placed a trifle in front of the centre. The
cartilage-j)it is very small, oblique, and just under the apex.

Having but a single valve for examination, and that probably immature, it would be
unwise to name it specifically; however, the record of its existence may possess some value.

REPORT ON THE LAMELLIBRANCHIATA. 49

Section B.

Necera curta, Jeffre3-s.

Necera curta, Jeffreys, Ann. and Mag. Kat. Hist., 1876, .ser. 4, vol. xviii. p. 495.
Necera curta, Jeffreys, Troc. Zuol. Soo. Loud., 1881, p. 943, pi. Ix.xi. fi;.;. 10.

Habitat. — Station 75, oft' the Azores, in 450 fathoms ; volcanic mud ; also
Station" 33, oft" Bermuda, in 435 fathoms ; other localities given by Jeffreys are
Stations 16 and 17, lat. 39° 55' N., long. 9° 56' AV., 994 fathoms; lat. 39° 42' N.,
long. 9° 43' W., 1095 fathoms ; and 24 to 28a of the "Porcupine" Expedition, 1870.

A single left valve from Station 33, measuring 9| mm. in length and 6^ in height,
agrees very closely with the figure cited aljove. This, too, is the specimen referred to
b}^ Jeffreys in the Proc. Zool. Soc. Lond. {loc. cit.). It exhibits one slight difference,
namely, in lacking the radiating striae on the anterior side. I think it likely that this
may be the same species as that referred Ijy Dall to Necera costellata (var. corpidenta)}

A perfect shell containing the animal, from Station 75, shows that the right valve
is rather smaller than the left, the ventral margin of which projects slightly beyond the
other.

Necera fallax, n. sp. (PI. X. figs, -l-'lh).

Testa tenuissima, giobosa, antice acute rotundata, postice breviter ro.strata, incre-
menti lineis striata, liris radiantibus teuuibus postice instructa. Margo dorsi anticus
arcuatus, valde declivis, j^osticus paulo concavus, obliquus. Margo inferior late curvatus,
postice leviter sinuatus et crenulatus. Umbones leves, paulo post medium collocati.
Dens lateralis posticus valvse dextrse elongatus, uscj[ue ad rostrum productus. Pagina
interna subnitida, postice radiatim subsulcata.

This species is rather globose, somewhat inequilateral, thin, narrowed to a sharply
rounded end in front, contracted and shortly beaked behind. It is .smooth towards the
umbones, sculptured elsewhere by fine lines of growth, and ornamented upon the hinder
half of the valves with aljout sixteen fine radiating lirae, of which those upon the
beaked extremity are the finest. The anterior dorsal outline is rather longer than the
posterior, much sloping and excurved, the hinder, on the contrary, being obliquely con-
cave. The ventral margin is broadly arcuate, with the exception of a faint sinuation at
the rostrum, where it is somewhat crenulated. The l)eaks are smooth, only slightly
prominent, and to the naked eye appear to have a posterior inclination, but in reality
are turned at the apex towards the front. The hinder lateral tooth of tlie right valve is
rather long, extending to the commencement of the narrowed extremity. The interior

' Vide Bull. Mus. Comp. Zool., vol. ix., Xo. 2, p. 110.
(zOOL. CHALl,. EXP. PART XXXV. 188-5.) Mill 7

50 THE VOYAGE OF H.M.S. CHALLENGER.

of the valves is sliallowly radiately grooved towards the posterior end, and exhibits a
moderately strong supporting ridge beneath the iimlio.

Length 7 mm., height 5, diameter 3;^.

Habitat. — ^Station 185b, east of Cape York, in 155 fathoms ; coral sand.

Section E.

NecBva teres, JefFre5-s (PI. X. figs. 3-3&).

Xewra teres, Jeffreys, Proc. Zool. Soc. Lond., 1881, p. 939, pi. Ixxi. fig. 2.

Testa tenuis, semipellucido-albida, serica, giobosa, rotundato-triangularis, postice
breviter rostrata, sequivalvis, sequilateralis, ad extremitatem posticam hians. Margo
dorsi anticus declivis, vix excurvus, posticus oblic^uus, concavus. Ventris margo late
arcuatus, prope rostrum leviter sinuatus. Valvse concentrice tenuiter striatge, carina
obliqua, filiforme, radianti, I'ostrum dissecante, ad iustructae, liriscjue paucis aliis
teuuibus radiantibus inter carinam et marginem dorsi ornata3. Umbones nitidi,
mediocriter elevati, mediani, apicibus antice versis. Denies cardinales nuUi. Laterales
duo in valva dextra breves, lamelliformes, valde prominentes. Ligamentum obliquum,
latus posterius versus incliuatum, in loculamento insigne, postice acuminato, in.
valva .sinistra situm. Paoina interna nitida, radiatim striata. Cicatrix anterior
parva, postica major, porca rotundata valida intus marginata.

This species is rather globose, triangularly rounded, shortly beaked, and gaping
behind, thin, semitransparent-white, and exhiliits towards the lower outline, and upon
the rostrum, more or less of a thin fibrous epidermis. The valves are equal and have a
silky appearance, being sculptured with fine strias of growth. The beaked portion
terminates in a short curved truncation, and is divided down the middle by an oblique,
slightly arcuate thread-like carina, extending from the umbo to the lower end of the
rostrum. Between this keel and the dorsal margin, the surface is ornamented with a
fewer, finer, and less conspicuous radiating lirse, which are crossed by rougher lines of
growth than those upon the rest of the shell. The dorsal margin is moderately oblique
on both sides, being nearly rectilinear in front, and gently concave behind. The anterior
end and ventral outlines are regularly curved, but the latter, behind, under the rostrum,
is just faintly incurved or sinuated. The umbones are fairly raised, glossy at the tips,
which are curved over towards the front and situated midway between the extremities
of the shell. The right valve has a very prominent lamellar lateral tooth on each side
rather near to the apex, the posterior, after being suddenly truncate behind, is continued
in the form of a slightly elevated ridge, immediately under the dorsal margin, some
distance along the rostrum. There are no cardinal teeth in either valve. The left
valve has the margin thickened on both sides, especially in front of the umbo, near

REPOET ON THE LAMELLIBRANCHIATA. , 51

which there is a peculiar pit for the reception of the anterior lateral tooth of the other
valve. The ligament is directed obliquely backwards, and is sustained in the left valve
in a small but thickish process which juts out distinct from the dorsal margin. The
interior is glossy, but marked with shallow radiating grooves or striae, which are even
more or less visible externally, owing to the transparency of the shell. The anterior scar
is small, the posterior rather larger, and margined on the inner side in' a strong rounded
ridge descending from above, under the dorsal slope.

Length 10 mm., height 7, diameter 4f.

Habitat. — Station VIII., oil' Gomera, Canary Islands, in 620 fathoms ; \olcanic mud.

The shells here described have been referred by Jeffreys ^ to his Necera infiata,
which, however, upon examination, proves quite distinct. The form of that species is
somewhat difi'erent, the right valve possesses " a small upright triangular cardinal "
tooth, and there is "a long laminar lateral on the posterior side " in the left, both
of which are wanting in these specimens, which differ also in lieiug radiately lii-atc
upon the rostrum and in some of the hinge-characters. Smce writing the above
description, I have had an opportunity of examining the type of this species, and find
that these Challenger specimens are undoubtedly conspecific.

Section F.

Nemra hrazieri, n. sp. (PI. IX. figs. 3—36).

Nemra {Rlunomya) rugata, Angas («o« A. Adams), Proc. Zool. Soc. Lund., 1867, p. 914.

Testa parva, elongata, sublonge rostrata, iusequilateralis, mediocriter convexa, alba,
lamellis tenuissimis coucentricis, supra rostrum coarctatis minusque elevatis instructa.
Margo dorsi anticus valde declivis, leviter arcuatus, posticus concavus, elongatus. Margo
inferior antice et in medio arcuatus, postice baud profuude sinuatus. Eostnim augustum,
rotunde truncatum, bicarinatum, valvse relicpio impressione levi notatum. Umboues parvi,
subconici, vix involuti, antemediani. Dentes laterales valvse dextrse breves, valde erecti,
prope apicem coUocati. Yalva sinistra tul)erculo dentiformi, paulo ante apicem mimita.

The shell of this species is small, rounded in front, and terminates posteriorly in a
moderately long and narrow beak. It is not very convex, rather inequilateral, white,
and not glossy. The valves are somewhat unequal in size ; the right is the smaller,
of a narrower appearance, and falls within the ventral margin of the left when
the valves are closed. They are marked posteriorly with a broad shallow depression
radiating from the uml)o to the ventral margin, and marking off the rostrum. The
sculpture consists of from twenty to thirty slender concentric lamellae, which become
crowded and less erect towards the depression, and upon the beak. This exhibits a faint

> rnc. Zool Soc. Loud., ISS], ].. 94-2.

52 . THE VOYAGE OF H.M.S. CHALLENGER.

ridge down the middle from the apex to the lower extremity, and a more distinct keel
nearer the dorsal mari,nn, marking oft' a smooth upper area. The front dorsal margin is
veiy oblique, somewhat curved, and shorter than the jjosterior, which is less sloping and
rather concave. The ventral outline is widely arcuate in front and at the middle, but
shallowly sinuate at the depression. The umbones are small, only slightly raised above
the hinge-line, hardly incurved, and, at the extreme tip, do not appear to incline either
anteriorly or posteriorly, although, when the valves are viewed externally, they curve
over towards the hinder .side. The right valve has a short Imt very erect lamellar
lateral tooth on each side near the umbo, the posterior, however, is prolonged under
the dorsal margin, in the form of a ridge, some distance along the rostrum. It also has,
just in front of the apex, a small triangular dentiform projection of the dorsal margin.
The left valve has no lateral, but a single thickish tubercular denticle, just in front of
the apex. The ligament is small, oblique, and posteriorly inclined, not in a prominent
process, but attached to the inner surface of the shell. The interior is glossy, exhibiting
more or less of the external concentric ribbing, especially in the right valve. The
muscular impressions are indistinct.

Length 6 mm., height 3f, diameter 2.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms (Challenger) ; Moreton Bay
(British Museum).

Section K.

Necera clavicidata, Dall (PI. IX. figs. 8—8/').

Necnra daviailala, Dall, Hull. Mus. Comp. Zoul., vol. ix., Xo. 2. p. 11 2.
Habitat. — Station 33, oft" Bermuda, in 435 fathoms ; coral mud.

None of the Challenger specimens are as large as that descriljed by Dall from
Station 44 of the " Blake " Expedition, the largest being only 6 mm. in length. The
right valve has a singular acute (almost hooked) denticle just in front of the apex, the
left l^eing entirely without teeth. The great feature of this species is the peculiar shelf-
like expansion within the posterior dorsal margin, the special use of which is at present
a matter of conjecture. It may be for the reception of the hinder adductor muscle,
although I am inclined to believe such is not the case.

Necera congenita, n. sp. (PL X. figs. 1-1/*).

Testa NecercB davicidatw similis, sed angustior, minus convexa, postice latius
rostrata, margine dorsi postico rectiusculo, ventrali postice vix sinuato, clavicula interna
magis elongata, et ligamenti fossa angustiori instructa.

REPORT ON THE LAMELLIBRANCHIATA. 53

This species, on accoimt of the internal wlielf-like process l)eueatli tlie posterior dorsal
margin, is <;loseIy related to Xewra daviculata of Dall, and may best be recognised by
a comparative description. It is less globose than that sjjecics, a little narrower, more
broadly rostrate behind, the ventral margin being regularly (mrved, and without a
shallow posterior sinuation, and the dorsal outline, behind the beak, scarcely at all
incurved. The umbones are placed more forward than in Xeaixi daviculata, and do
not curve over so much towards the posterior end. Within I find two differences. In
the fir.st place the " clavicle " is longer, and commences at the upjier end under the
dorsal margin, whilst in Ball's species the inner margin of the clavicle is joined al)0ve to
the process which receives the internal hinge-cartilage. The second distinction consists
in the narrower character of this process, which also is almost parallel witli the hinder
dorsal edge, whilst in Necera daviculata it juts farther out into the shell.

Length 4 mm., height 2f, presumed diameter 2^.

Ilahitat. — Station 33, otf Bermuda, in 435 fathoms ; coral mud.

Only a single left valve is. at present known of this species, and that probal)ly not
full grown. Were there no other diflerence except that of form I should have hesitated
to have separated it from Necera daviculata ; seeing, however, that the clavi('le and
hinge are also dissimilar, I have no doubt of this being a distinct species. It is
unfortunate that no right valve is at hand for examination, for most likely a modification
of the peculiar sul)hooked tooth, met with in the allied form, would occur in this
species. I am exceedingly sorry to have to record the complete destrviction, through the
(;arelessness of a servant, of this particularly interesting valve since it was returned to me
by the artist.

Section M.
Necera frag ilissima, n. sp. (PI. IX. figs. l-l/>).

Testa magna, tenuissima, ovata, postice Ijreviter rostrata, globosa, hand nitida, alba,
ina3i|uilateralis, liris radiantiljus tenuibus instructa, incremeutique lineis striata,
^largo dorsi auticus altus, supra umbones productus, posticus paulo excavatus. Latus
anticum superne obliquum, parum arcuatum, ad extremitatem subacute rotundatum.
3Iargo ventralis late curvatus, postice sub rostro leviter sinuatus. Rostrum breve,
liris radiantibus obsoletis ornatum, superne pone umbones aream angustam impressam
exhibens. Umbones postmediani, ad apicem acuti, paulo supra marginem product!.
Yalva dextra postice vix dentata. Pagina interna parum nitida, radiatim sulcata
et striata.

This species is excessively fivagile, rather large and inflated, inequilateral, ovate-
rostrate, not glossy exteriorly, white, and sculptured with numerous fine radiating

u4 THE VOYAGE OF II.M.S. CllALLEJS'UElt.

ridges, of which those upon tlie surfece between tlio middle of tlic valves and the
commencement of the rostrum are thicker than the rest, those upon the beak itself
beiiio- almost obsolete. In addition, it is ornamented with the lines of (irowtli, which,
in some places, are so strong as to produce a slightly cancellated appearance. The
front dorsal margin is much elongated and a little curved, the posterior, on the contrar)-,
being slightly concave and just a trifle oblique. The anterior end is obliquely sloped
above, with a very small curve, and terminates in a moderately sharply rounded
extremity. The ventral outline forms a broad curve except beneath the rostrated end,
where it is feebly sinuated. The beak is broad, rather short, curvedly truncate at
the end, and exhibits above, a narrow, slightly sunken dorsal area. The umbones nie
moderately large and acute, recurved, somewhat raised above the hinge-line, and
located rather in advance of the centre. The hinire mioht be said to l)e toothless,
although in the right valve there is a very insignificant ridge, starting from the
ligament-pit and continued a little way parallel witli the posterior dorsal margin, M'hich
might be regarded as an incipient lateral tooth. The ligament is small, short, and
oblique, inclining towards the anterior end. The interior is not very glossy, but
exhibits radiating grooves and striae corres2:)on(ling to the external ridges and lira;.
The hinder muscular scar is more distinct than the front one, ami Imiilei'ed anteriorly
by a thickened ridge.

Length 20 mm., height 12, diameter 9.

Habitat. — Off Prince Edward Island, in 300 fathoms.

This is a large and very fragile species, in many respects similar to Neara ciuia.
Jefireys. It is perhaps a little longer in proportion to the height, has more distinct
lii-se on the anterior half of the surface, a narrow sunken dorsal area, and lacks the
*' short strong triangular lateral " tooth on the posteiior side of the ri-ht Aahc wliicli
occurs in that species.

Puroiiii/a, Forbes.

Poromya australis, u. sp. (PI. XI. figs. 2—26).

Testa parva, aequilateralis, tenuis, albida ; margo dorsi utrinquc valdc declivis,
antice concaviusculus, postice Icviter convexus. Valva dextra mediocriter convexa, in
regione lunulari concave depressa, prope marginem dorsalem posticum carinata, undique
granulata, granulis confertis, erectis, in quincuncibus digestis. Umbo prominens, ad
apicem levigatus, antrorsum versus. Dens cardinalis unicus validus, erectus, infra
apicem locatus. Pagina interna alba, nitida, leviter margaritacca.

Only a single right valve of this species was obtained. It is al)out as long as high,
rounded at both ends, and along the ventral margin it is more gentl}' curved. It is

REPORT ON THE LAMELLIBRANCHIATA. 55

tliininsh, equilateral, morlevately convex, white, and ornamented with innumerable minute
elevated granules arranged in (|uincuncial foshiou. The dorsal margin is considerablj'
ol)li(|ue on both sides of the ])rominent beak which is well curved over towards the
iVoiit, and sniDOtli and glossy at the tip, in front of wliicli there is a lunular depression,
which is not, however, defined by a line. The anterior dorsal slope is a trifle concave,
the posterior side, on the contrary, l)eing slightly convex, exhibiting a sharpish keel or
ridge very close to the edge, marking oft" a linear dorsal area. The single cardinal
tooth is large, strong, erect, and situated immediately beneath the apex of the umbo.
The interior of the valve is whitish and somewhat pearl)^.

Length 4|- mm., height 4^, diameter of valve 1|^.

Habitat. — Station 185b, east <jf Cape York, North Australia, in 155 fathoms ; coral
sand.

This is a shorter shell than the European Povomija granidata of Nyst, with more
sloping dorsal margins and a more c-urved ventral outline. It is also more coarsely
granulated, and the pit containing the internal ligament is smaller and more equUater-
ally triangular.

Povoiiiija Iwvis, n. sp. (I'l. XI. tigs. 3—36).

Testa insequilateralis, ovata, antice pauIo acuminata, postice latior, leviter sub-
truncata, alba, tenuis, nitida, incrementi lineis levibus striata, undicj^ue microscopice
subpunctata. JMargo dorsi utrinque declivis, postice subrectUinearis, antice leviter
excurvatus, prope umbonem contractus, lunulam parvam concavam formans. Margo
ventris late arcuatus. Umbones parvi-, paulo supra marginem dorsalem producti,
alic|uanto post medium siti. ^"idva. dextra dente unico subvaUdo infra umbonem
instructa, lineaque cardinis anti(;e profunde sulcata. Proxime sub margine dorsali pone
umbonem est liganienti sulcus parvus hand })rofundus. Pagina interna nitida, sul)-
margaritacea, ladiatim substriata.

Of this species only tluee right valves are at present known. It is of an ovate
form, a little acuminate in front, broader and somewhat truncated behind. It is not
very convex, rather inecj^uilateral, the anterior side being the longer. It is thinnish,
white, glossy, sculptured with very fine lines of growth, and everyA\'here exhibits a micro-
scopic shagreened surface, only \asible under a compound lens. The front dorsal margin
is a little curved and sloping, the posterior being shorter, straighter, and more oblic[ue,
and turned at right angles to the rest of the valve, forming a narrow dorsal area.
The ventral outline is regularly and widely arcuate, ascending equally at both ends.
The l>eaks are small, slightly raised aljove the hinge-line, are situated behind the centre,
and curve towards the front over a small concave lunule. The interior is glossy,
semipearly, and finely radiately substriated, especially towards the lower margin. There

56 THE VOYAGE OF 11. M.S. CHALLENGER.

t
is a single strongish tootli in the right valve just Lenoath the uml>o, with a large deep
triangular excavation behind it, the hinge-plate being rather deeply grooved on the anterior
side. Immediately under the dorsal margin, a little behind the beak and above the
triangular excavation mentioned above, there is a small shallow elongate pit, no doubt
for the reception of a small internal ligament. The muscular impressions are indistinct.

Length 7 nnn., height b\, presumed diameter of a perfect specimen 4.

Habitat. — Station 185b, east of Cape York, North Australia, in 155 fathoms; coral
sand.

Although not minutely granulated like the typical forms of Poromija, still, in the
composition of the hinge, this species, so far as one can judge from right valves only,
accords with that genus. The interior has a similar semipearly character, and is
radiately substriated, so that the location is probablj' correct.

Subfamily Myin^.

Mya, Linne.
Mj/a sp.

Habitat. — Flinders Passage, Torres Strait, in 7 fathoms.

Only a minute left valve of a species of Mya was obtained at this locality. It is
not unlike Mya japonica in outline, and possibly it may be the young of that form.
As no species of the genus has been recorded from this district, its occurrence may be
worthy of mention.

Family M a c t r i d .e.

Subfamily Lutrariin.e.

Pacta, Gray.

«> Raeta pulcheUa, (Adams and Reeve).

Poromi/a piildiella, Adams and Reeve, Zool. Voy. Samarang, p. 83, pi. xxiii. fig. 1.
Raeta 2Julchel.la, H. and A. Adams, Gen. Moll., vol. ii. p. 386.
Madra ronfralis, De.shayes, Proc. Zool. Soc. Lond., 1854, p. 69.
Mudra rostralU, Reeve, Con. Icon., vol. viii. pi. xxi. fig. 119.

Habitat. — Off Yokohama, in 8 to 14 fathoms ; and Station 233c, off Japan, in
12 fathoms.

This species was originally described from specimens dredged off the shores of
Borneo, and again as Mactra rostralis, from Japanese examples. It is more elongate
than the young of the American Pacta canaliculata, and somewhat more equilateral.

REPORT ON THE LAMELLIBRANCHIATA. 57

Subfamily Mactrin.e.
Mactra, Linue.

Mactra {Mactrinula) pUcataria, LiiiiR'.

Mactra iMcataria, Linne, Syst. Nat., ed. 12, p. 1125.

Mactra pUcataria, Chemnitz, Conch. -Cab., vol. vi. p. 213, pi. x.x. figs. 202-204.

Mactra plicataria, Reeve, Con. Icon., vol. viii. fig. 26.

Mactra {Mactrinula) jilicataria, Kobelt, Illust. Conch., p. 324, pi. xciii. fig. 8.

Mactrinula pUcataria, H. and A. Adams, Genera, vol. iii. pi. xcix. figs. 2, 2a.

Mactrinula plicataria, Chenu, Manuel Conch., vol. ii. p. 55, fig. 226.

Habitat. — Cape York, North Australia, in 3 to 12 fathoms (Challenger); Java
(Linn.); Sumatra (Reeve); Tranquebar (Chemnitz).

Only a single small specimen about half an inch in length was obtained. This is
not quite typical, having the concentric riblets more or less obsolete, except down the
anterior side, in this respect more like Mactra Uvvis, Chemnitz, which I believe is
another form of this species.

Mactra [Mactrinula) de2)ressa, Reeve.

Mactra depressa (ISpengler) (teste Reeve), Skrivt. af Naturhist. Selskabet, 1799, vol. v. p. 118.
Mactra depi-essa, Reeve, Conch. Icon., vol. viii. fig. 67.
Mactra ovalina, Reeve (? Lamarck), Conch. Icon., fig. 66.

Habitat. — Port Jackson, in 2 to 10 fathoms (Challenger and G. F. Angas); also
Port Philip (Angas and Brit. ]\Ius.).

I see no sufhcieut reason for separating the above two forms. Probably Reeve was
influenced by the localities attached to the specimens in Cuming's collection. " West
Columbia " I merely regard as one of the numerous geographical errors which occur
throughout that collection, many of which unfortunately have found their way into print in
the works of Reeve and Sowerby. Mactra angulifera, Deshayes, is scarcely sufficiently
distinct to warrant its specific separation. The figure in Delessert's Recueil, pi. iii.
figs. 7a, b, is a verj' cUfierently shaped shell to that represented in the Conchologia
Iconica.

I have little doubt that Reeve's identification of this species with the Mactra
depressa of Spengler is incorrect. It is described by the latter author as having a
sulcated lunule and a liueated area (" vulva arcuata, sulcata, ano lineato "). It is also
characterised as equilateral, the posterior carinse are not mentioned, and it is said
to come from the coast of Guinea. The name " depressa " has been subsequently
employed by Deshayes for a fossil species (Coq. foss. de Paris, vol. i. p. 32).

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) ^I HI 8

58 THE VOYAGE OF H.M.S. CHALLENGER.

Mactra incarnata, Deshayes.

Madra incarnata (Deshayes), Reeve, Conch. Icon., vol. viii. fig. 6L
TrigoufUa incarnata, H. and A. Adams, Genera Rec. JIoll., vol. ii. p. 376.
Tricjimalla incarnata, Tryon, Amer. Journ. Conch., vol. iii., Appendix, p. 37.

Habitat. — Station 212, .south of the Philijjjjine Mands, iu 10 fathoms; saud.

This species was described from specimens said to have been obtained at Swan
River. Only six small not haLf-grown valves were collected by the Challenger at the
above locality. At this age they appear rather more trigonal than when adult, and
exhibit more rosy radiation in the interior of the valves. The species is closely
related to Mactra eximia of Deshayes, which, however, is a somewhat higher shell,
having a more strongly curved basal margin and somewhat coarser sulci on the lateral
areas.

There are three or four species which are characterised with similar lateral grooving,
and border rather closely on the present form. Among these may be mentioned
Mactra semistriata, Deshayes, Mactra eximia (already referred to), Mactra antiquata,
Spengler, and Mactra mera, Deshayes, the two last being unquestionably one and
the same shell. The distinction between those and other closely allied forms of
Mactra may be very trifling, still they appear fairly constant, each locality producing
its variety.

Mactra isaheUeana, d'Orbigny.

Mactra isabdleana, d'Orbigny, Voy. Ainerique M^rid., vol. v. p. 509 ; Atlas, vol. ix. pi. Ixxvii.

figs. 25, 26.
Mulinea isabelliana (d'Orbigny), Tryon, Amer. Journ. Conch., vol. iii.. Appendix, p. 31.

Habitat. — Station 321, off Monte Video, in 13 fathoms; mud.

D'Orbigny says that this species is found at all points near the mouth of the Eiver
Plate at Maldonado, at Monte Video, and on the oj)posite coast at Cape San Antonio.

It is a moderately solid shell, a little inequilateral, somewhat trigonal, and generally
more acute posteriorly than in front. It is of a whitish-brown colour, and more or less
covered with a yellowish-olive epidermis. The surface of the valves is sculptured by
concentric strise of gro'ni:!!, and generally exhibits, here and there, stronger grooves and
elevations, which may indicate periods of arrested increase. The jjaUial sinus is subject
to some variation, in some instances being deeper than in others, but it never
apparently extends nearly half-way across the valves. The external ligament is minute,
situated above the internal cartilage, and is separated from it by a narrow shelly
partition.

REPORT ON THE LAMELLIBRANCHIATA. 59

Mactra achatina, Chemnitz.

Madra achatina, Chemnitz, Conch. -Cab., vol. xi. p. 218, pi. cc. figs. 1957, 1958.
Mactra achatina, Reeve, Conch. Icon., vol. viii. pi. xii. fig. 51.
Mactra maculosa, Lamarck, Anim. Sans Vert., ed. 2, vol. vi. p. 100.
Mactra maculosa, Hanley, Cat. Reo. Shells, pp. 29 and 340, pi. xi. fig. 27.
Mactra ornata. Gray, Ann. and Mag. Nat. Hist., 1837, vol. i. p. 371.
Mactra ornata, Eeeve, loc. cit., pi. xiii. fig. 58.

Habitat. — Admiralty Islands, in 16 to 25 fathoms (Challenger) ; Philippine Islands
(Reeve), Ceylon, and Nicobar Islands (Chemnitz) ; var. ornata, China (Gray) ; Ceylon
(E. W. H. Holdsworth in Brit. Mus.).

Among the synonymy of this species given by Reeve and copied by Conrad (Amer.
Journ. Conch., vol. iii., Appendix, p. 35) I find mentioned Mactra maculata as of Hanley.
The species referred to by the latter author is not the Mactra achatina, but the true
Mactra macnlata of Chemnitz, which is a very different shell. It is figured by Reeve,
Conch. Icon., fig. 56, and again as Mactra reevei, Deshayes, on pi. xvi. fig. 85.

The Mactra ornata of Gray I regard as the typical form of this species, and the shell
figured by Reeve (fig. 51) as a variety. Specimens in the British Museum from Ceylon,
one of the localities mentioned by Chemnitz, agree better as regai'ds colour and form
wdth the figure and description in the " Conchylien-Cabinet " than those from the
Philippine Islands and Admiralty Islands.

Mactra incerta, n. sp. (PI. V. figs. 7— 7c).

Testa mediocriter convexa, ovato-subtrigona, paulo inaequilateralis, tenuiuscula, nitida,
levigata, utrinque umbones versus radiatim sulcata, albida, radiis latis interruptis fuscis
variegata. Margo dorsi anticus elongatus, oblique leviter couvexus, posticus A^alde
declivis, parum arcuatus ; margo inferior late curvatus. Umbones acuti, ad apicem
fuscescentes, paulo post medium collocati. Cardo albus, dentibus lateralibus gracilibus
munitus. Pagina interna nitida, coloribus externis tincta. Sinus pallii mediocris,
rotundata.

This little species has the anterior side rather longer than the posterior, the former
being narrowed towards the end, where it is sharply rounded, and the latter broader,
obliquely suljtruncate, terminating in a rounded angle at the base. It is a thinnish shell,
rather glossy, with very little sculpture upon the greater portion of the surface, but
rather strongly grooved laterally on both sides of the beaks. The ground-colour is
whitish, copiously stained with brown in the form of broad interrupted rays which are
faintly obscured by an excessively thin epidermal film. The front dorsal margin is a
little convex and descends obliquely, the posterior also being slightly excurved, but much

60 THE VOYAGE OF H.M.S. CHALLENGER.

more suddenly sloping. The lower outline is very gently curved, rising rather higher
in front than behind. The beaks are small, brown at the tips, placed a little behind the
centre, and raised a trifle above the hinge-line. The hinge-plate and the teeth, including
the slender laterals, are white. The interior is somewhat glossy, of the same colour as
the exterior, showing a pallial sinus, sharply rounded at the end, and reaching a little more
than a third of the length across the valves.

Length 15 mm., height 10, diameter 7.

Ilahitat. — Admiralty Islands, north-east of New Guinea, in 16 to 25 fathoms.

The single specimen under examination may not represent the adult state of this
species ; but, judging from its general appearance and the somewhat thickened inner
margin of the valve, I am of opinion that it does not attain a large size. It must not
be confounded with the young of Mactra achatina, also met with at the same locality.
That species has the hinder portion of the valves longest, and lacks the strong grooving
on each side of the umbones.

Mactra decora, Deshayes.

Madra decora, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 63.
Mactra decora, Reeve, Conch. Icon., vol. viii. fig. 80.

Habitat. — Banda Island.

A single specimen from this locality may possibly be the young form of this species,
although I hesitate to afiirm positively that such is the case. The species attains a
larger size than the example figm-ed by Reeve, a specimen in the Cumingian collection
having a length of 57 mm.

Mactra pusiUa, A. Adams (PL V. figs. 8-8r).

Mactra pusilla, A. Adams, Proc. Zool. Soo. Lond., 18.55, p. 226.

Testa ovato-trigona, fere seq^uilateralis, utrinque subacuminata, tenuis, dilute caeruleo-
alba, radiis olivaceo-fuscis numerosis plus minusve distinctis ornata. Umbones mediani,
acuti, pur[3urascentes. Ai-ea dorsalis utrinque alba, fusco margiuata. Yalvse nitidse,
incrementi lineis tenuibus striatije, utrinque marginem dorsalem versus subfortiter et
confertim sulcatiB. Margo dorsi anticus valde declivis, jjaulo convexus, posticus
aliquanto convexior, subsequaliter obliquus. Ventris margo regulariter late arcuatus.
Pagina interna livido-purpurascens, prope umbones cseruleo-albida, marginem inferiorem
versus dilute fuscescens vel cervina. Pallii sinus mediocriter profundus, vix ad medium
attingens, ad extremitatem acute rotundatum.

REPORT ON THE LAMELLIBRANCHIATA. 61

This is a thinnish species, nearly equilateral, ovately trigonal, longer than liigli, some-
what acuminate at both ends, more especially posteriorly. It is rather glossy, very
finely striated by lines of growth, and sculptured on both sides beneath the dorsal line
with somewhat strong sulci, which become gradually coarser as the shell increases. The
general tone of the valves is light fawn, varied with numerous narrow olive-brown rays,
and purple tips to the umbones. The dorsal area has a lanceolate white space in front
of the beaks, and a narrower one behind them, which are bordered with a brownish colour.
The dorsal margin is very oblique and only slightly curved in front, but rather more
arched and about equally sloping behind. The lower outline is regularly and broadly
arcuate, forming anteriorly with the upper slope a rather sharply rounded extremity, the
opposite end being roundly angulated. The interior of the valves is livid purplish, paler
towards the margin, which is fawn coloured, and bluish-white beneath the umbones.
The hinge-plate and the teeth are white. The pallial sinus moderately deep, some-
what sharply rounded at the end, • and does not reach quite half-way across the
valves.

Length 31 mm., height 21, diameter 12^.

Habitat. — Brisbane water, Queensland, di-edged at a depth of 5 fathoms on a sandy
and shelly bottom by J. Macgillivray during the voyage of the " Eattlesnake ; " also
Port Jackson, New South Wales, in 4 to 18 fathoms (Challenger) ; Moreton Bay
(A. Adams).

This is possibly the species referred by Angas ^ to Mactra luzonica of Deshayes, to
which it is very closely related. That species is, however, a somewhat thicker shell, a
trifle more elongate, having the hinder side rather longer than the anterior, whilst, in the
present species, the latter portion is slightly the larger. It is more strongly striated,
especially towards the anterior end, where the valves are distinctly concentrically
sulcate. It is also almost totally devoid of radiating markings, has no whitish mark
beneath the umbones in the interior, and has a smaller and shorter paUial sinus. It is
said to have been found at the Island of Luzon, and specimens were collected on the
coast of Arakan by W. T. Blanford, Esq., who liberally presented a set, together with a
very valuable collection of shells from that country, to the British Museum.

The types in Cuming's collection found at Moreton Bay by Mr. Strange are young
shells, and of a paler tint than more adult specimens. The interior also lacks the livid
purplish colour so characteristic of the full-grown shell, and the beaks are paler than
usual. In aU other respects there is no difference, the form, sculj^ture, hinge and
pallial sinus corresponding exactly with the larger specimens from Port Jackson and
Brisbane. But little attention must be paid to the colours ascribed to this species
by its describer, for I was once informed by Mr. G. F. Angas that ^Ir. A. Adams was
colour-blind.

1 J'roc. Zoul. Hoc. Lund., 1867, ]'. UlU.

62 THE VOYAGE OF H.M.S. CHALLENGER.

Mactrajacksonensis, n. sp. (PI. V. figs. 9-9&).

Trigonella pusilla, Angas (non A. Adams), Proc. Zool. Soc. Lond., 1867, p. 916.

Testa parva, paulo inaequilateralis, triangularis, albida, radiis paucis fuscis plus minusve
distinctis ornata, tenuis, nitida, striis concentricis tenuibus sculpta. Margo dorsi utrinque
valde declivis, vix arcuatus vel subrectus ; margo veutris late arcuatus, parum ascendens.
Cardo angustus, dentibus gracilibus munitus. Pallii sinus parvus, minime profundus.

This species is of small size, triangular, considerably acuminate behind, and rather
more obtusely rounded in front. It is a little inequilateral, the posterior side being a trifle
longer than the anterior. It is thin, glossy, finely concentrically striated, the striae being
about as fine at the sides as on the centre of the valves. It is whitish, varied with about
six more or less distinct brownish rays. The dorsal margins are almost rectilinear, and
rather sloping, especially the posterior, which is a trifle longer than the anterior. The
umbones ate small, acute, white, and defined on each side by brownish rays. The interior
of the valves is very similar in colour to the exterior, and exhibits a very small delicate
hinge and a very shallow pallial sinus, extending only about one fourth of the length
across the valve.

Length 14^ mm., height lOg, diameter 6.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

This species must not be confounded with the young form of Mactra pusilla. It may
easily be distinguished by the following difl'erences. It is more acute behind and has
the posterior side longer than the anterior, whilst in Mactra pusilla the relative sizes are
reversed. The present species too has pale imibones, also lacks the conspicuous sulci on
each side upon the dorsal areas, and has a smaller pallial sinus.

Family A n a T i n i d jj.

Subfamily Pandorin^.

Ca'lodon, Carpenter.
Coelodon elongatus. Carpenter.

Caelodonelongatus, Carpenter, Proc. Zool. Soc. Lond., 1864, p. 600.
Coelodon elongatus, Carpenter, Moll. West. N. Amer., p. 229.

Habitat. — Flinders Passage, North Australia, in 7 fathoms.

The shells originally described by Carpenter were from China and Borneo. The
single specimen from the aljove locality difi'ers in one or two points which are not, I
consider, of specific importance. The hinder portion of the dorsal line is rather less

REPORT ON THE LA.MELLIBRANCHIATA. 63

incurved, the anterior less oblique, and the left valve has a slight keel extending a short
distance oblicpely from the umbones which does not occur in the three specimens
examined by Carpenter. These differences probably would not prove constant could we
study a large number of examples. In its excessive flatness and the character of the
hinge it perfectly corresponds with this species. Ccelodon delicatulus} a Japanese
species, has a similar umbonal ridge, but is rather different in form, and has another
description of hinge.

Myochama, Stutchbury.
Myochama anomioides, Stutchbury.

Myochama anomioides, Stutclibury, Zool. Journ., vol. v. p. 9Y, Tab. Suppl. 42, figs. 1-4.
Myochama anomioides, Hancock, Ana. and Mag. Nat. Hist., 1853, vol. xi. p. 287, pi. xi.

(animal).
Myochama anomioides, Chenu, Man. Conch., vol. ii. p. 52, fig. 219.
Myochama anomioides, Woodward, Man. Moll., pi. xxiii. fig. 13.
Myochama anomioides, Reeve, Conch. Icon., fig. 4c only.

Myochama liejypelliana, A. Adams, Proo. Zool. Soc. Lond., 18.52, p. 90, pi. xv. fig. 1.
Myochama liepjM'lUaiia, Reeve, Conch. Icon., fig. 2.

Habitat. — Port Jackson on Pectunculus holosericus and Trigonia lamarckii, in 2 to
10 fathoms; also at Station 162, off East Moncceur Island, Bass Strait, in 38 fathoms;
sand and shells ; on Pectuncidus beddomei.

I do not find any good characters distinguishing Stutchbury's Myochama anomi-
oides and the Myochama keppelliana of A. Adams, and I am also inclined to think that
another set of species so-called, namely, Myochama stutchhuryi, A. Adams, Myochama
tahida, Reeve, and Myochama tra)7sversa, A. Adams, merely differ from the rest
in having the radiating costse finer. I feel, however, no hesitation in pronouncing the
three last mentioned forms as one and the same. The remaining species, Myochama
strangei of A. Adams, is a very distinct shell from any of those mentioned above,
having a peculiarly WTinkled and malleated surface, and moreover of a different colour.
I would here remark that Reeve is totally wrong in placing Myochama transversa as a
synonym of Myochama strangei, the latter being correctly figured on PI. I. fig. \h.

The type of Myochama transversa still preserved in the Cumingian collection, does
not appear in Reeve's Monograph, but was first of all figured in the Proc. Zool. Soc. Lond.,
1850, pi. viii. fig. 1, the drawing being enlarged, and subsequent!}^ in the same work for
1852, pi. XV. fig. 3, this figure representing the specimen of its natural size. I do not
agree with Reeve in considering the right hand specimen of figure 3 on his plate distinct
from the shell on the left, both in my opinion being forms of Myochama transversa, also
represented by figs. 4a and 46, Myochama anomioides being delineated by fig. 4c only.

» (A. Adams, MS.\ Carpenter, Proc. Zoo}. Soc. Lond., 1864, p. GCO.

64 THE VOYAGE OF H.M.S. CHALLENGER.

Myodora, Gray.

Myodora pandoriformis, (Stutchbiuy).

Anatiua jiandorifnrmis, Stutclibury, Zool. Journ., vol. v. p. 99, Tab. Suppl. 43, figs. 3, 4.

Myodora 2)undoriform)s, Haiilej', Descrip. Cat. Eec. Biv. Shells, pi. x. fig. 9.

Myodora imndoriformis, Smith, Proc. Zool. Soc. Lend., 1880, p. 581.

Myodora pandoneformis, Eeeve, Conch. Icon., fig. 10 ; Proc. Zool. Soc. Lond., 1844, p. 93.

Myodora brev/'s, H. and A. Adams (non Sowerby), Gen. Eec. Moll., vol. iii. pi. xcviii. figs. 2, 2a.

Habitat. — Port Jackson, Sydney, 2 to 10 fathoms (Challenger, Stutchbury, and
Macgillivray) ; ]\Iiddle Harbour (Angas) ; Sydney Heads, 1 5 fathoms (Brenchley) ; Port
Philip (Brit. Museum).

This species is easily recognised from the rest of the genus by its transversely elongate
form, its comparative smoothness, and the excessive fineness of the microscopic sculpture.

Myodora hrevis (Sowerby).

Pandora hrevis, Sowerby, Appendix to Stutchbury's Sale Catalogue, p. 3, pi. fig. 2.

Anatina hrevis, Stutclibury, Zool. .Journ., vol. v. p. 99, Tab. Suppl. 43, figs. 1, 2.

Myadora hrevis, Eeeve, Proc. Zool. Soc. Lond., 1844, p. 93.

Myadora brevis, Eeeve, Conch. Icon., figs. 7a, h.

Myodora hrevis, Hanley, Cat. Eec. Biv. Shells, pi. x. fig. 13.

Myodora hrevis, Chenu, Man. Conch., vol. ii. p. 52, fig. 217.

Habitat. — Port Jackson, Sydney, 2 to 10 fathoms (Challenger, Stutchbury, and
Brenchley) ; Lane Cove, Farm Cove, and Mossman's Bay (Angas) ; Cape Upstart (Mus.
Cuming) ; New Zealand, Stewart Island, and Tasmania (Brit. Mus.).

The Myodora hrevis of Woodward's Manual of MoUusca, pi. xxiii. fig. 12, is the
Myodora striata of Quoy and Gaimard, and Messrs. H. and A. Adams' identification of
this species (Gen. Rec. Moll., vol. iii. pi. xcviii. figs, 2, 2a) is also incorrect, the shell there
delineated being Myodora pandoriformis. In my Monograph of this genus ^ I observe
that the form of this species is subject to considerable variation. This may be seen
by comparing the figure in the Stutchbury Sale Catalogue with that in the Zoological
Journal. The series of specimens in the British Museum, too, indicates how variable
this species is with regard to outline, the apical angle in some being much more acute
than in others. The microscopic sculpture consists of a very minute granulation, the
granules being of unequal sizes, and frequently transversely oblong. This granu-
lation is coarser than in the other species of the genus, and the almost total absence
of the radiating microscopic lines in all of them is remarkable. The Tasmanian
specimens are peculiar on account of the greater coarseness of the concentric raised ridges ;

^Proc. Zool. Soc. Land., 1880, p. 580.

EEPORT ON THE LAMELLIBRANCHIATA. 65

but in other respects they agree witli the normal Australian form, except that the
umbonal angle is rather less acute.

Myodora crassa (Stutchl)ury).

Anatina crasm, Stutchburv, Zool. Journ., vol. v. \\. 100, Tiili. Su|ipl. xliii. figs. .5, G.
Mijodora crassa, Reeve, Proc. Zool. Soc. Lond., 1844, p. 92.
Mi/odora crassa, Reeve, Conch. Icon., fig. 1.
Myodora crassa, Hanley, Roc. Biv. Shells, pi. x. fig. 6.
Myodora crassa, Smith, Proc. Zool. Soc. Lond., 1880, p. 581.

Habitat. — Port Jackson, Sydney, iu 2 to 10 fathoms (Challenger, Stutchbury,
Macgillivray, King) ; Middle Hai'bour (Angas).

Only one not quite full-grown right or deep valve was obtained by the Expedition.
The species, although small, is remarkable for its solidity, and the less flattened character
of the flat or left valve. The microscopic sculpture is fairly coarse, the radiating striae
being well marked. In addition to the single valve above mentioned, I have since
discovered three very small odd valves which possibly may be the young state of this
species. I find in them two ditferences, namely, a larger pallial sinus and no lateral
dental grooves in the right valves. Considering, however, the modifications in the
hinges of some bivalve shells resulting from age, I think it very possible that these
differences in the present instance may arise from a like cause.

Myodora trigona, Reeve.

Myodora trigona. Reeve, Conch. Icon., fig. 2 ; Proc. Zool. Soc. Loud., 1844, \). 92.
Myodora tincta. Reeve, Conch. Icon., fig. 5; Proc. Zool. Soc. Lond., 1844, p. 93.

Habitat. — Flinders Passage, North Australia, in 7 fathoms.

A single left valve from this locality diSers from the type from the Philippine Islands
merely in having the dorsal margins convergent at a rather less acute angle, so that the
form becomes rather more oblong, and a right valve is still less angular and partakes of
the form of an adult Myodora oblonga, Reeve. This species may only be the youug
form of a variety of that species, being mainly distinguished by rather finer concentric
sculpture.

Myodora sp.

Te.sta valva sinistra suba^quilaterali, triangulari, latere antico acute angulato, po-stico
oblique truncato, leviter concava, sulco prope margiuem dorsi posticum exarata, concentrice
sulcata, interstitiis subrotundatis, pone sulcum radiantem obsoletis, undique microscopice

(zool. chall. EXP. — PART xxxT. — 1885.) Mm 9

66 THE VOYAGE OF H.M.S. CHALLENGER.

interruptim eoncentrice striata, Margo dorsi utriiifjiie valde deseendens, subsequalis,
posticus rectiliuearis, anticus levissime couvexus. Margo ventralis late arcuatus, postice
Adx adsceudeus. Sinus pallii arcuatus, minime profundus. Pagina interna sulco radianti
unico notata.

There is but a single left or flat valve of this species in the collection. It is
triangular, nearly eqiiilateral, acute in front, shortly truncated posteriorly, a little
concave, concentrically grooved and lidged, the ridges being nearly obsolete behind an
impressed ray which runs from the acute umbo to the lower angle of the hinder trunca-
tion. The dorsal margins are about equal in length, and converge at an angle of about
60°. The hinder is c[uite rectilinear, except just behind the umlio, where there is the
faintest incurvation, the anterior being, on the contrary, slightly excurved. The lower
margin is ^videly arcuate, a little up-cur\'ing in front, and scarcely at all at the opposite
end. The internal surface is glossy, porcellanous, and marked with a single radiating
groove, extending from near the acute recurved beak to the side of the shallow sinus in
the pallial line.

Leno-th 7 mm., heio-ht 51.

Habitat. — Flinders Passage, Cape York, North Australia, in 7 fathoms.

The single valve here described approaches il/yoc?oro trigona,liieeYe. It is, however,
distinguished by the longer straight posterior dorsal slope, greater concavity of the
surface, and the more pronounced radiating groove.

Myodora sp.

Testa elongata, tenuis, paulo infequilateralis. Valva dextra mediocriter convexa
postice pone porcam radiantem ab uml)one ad extremitatem posticam decurrentem
ali(|uanto excavata, eoncentrice lirata, latere, antico rotunde subangulato, postico oblif^ue
truncate. Margo dorsi anterior obliquus, fere rectus, posticus paululum longior, leviterque
concavus, declivis. ]\Iargo ventralis latissime arcuatus. Sinus pallii modice profundus,
apice subacuto.

Only two right valves of this .species were obtained. They are very elongate, thin,
a Uttle inecjuilateral, finelj^ and subdistantly costate, the ridges disappearing at the
arcuate angulation which marks off a small depressed portion of the surface at the hinder
end. The dorsal margins are subequally oblique, and form at the umbo an angle of about
65°. The posterior is slightly the longer, and a little concave, the anterior being nearly
rectilinear.

The lower margin is very gently curved, and forms with the dorsal slope an acutely
rounded anterior extremity, the opposite end being broadly truncate in a slightly oblique

EEPORT ON THE LAMELLIBRANCHIATA. 67

direction. The microscopic sculpture is finer at the extremities than on the central
portion of the valves, where the radiating striae are clearly developed. The umbo is acute,
dii-ected towards the hinder end, and curves over towards the left valve. The pallial
sinus is fairly deep and acutely rounded at the end, and is touched by an impressed ray
descending from the beaks. The hinder muscular scar is cii-cular, rather high up, aud
larger than the anterior, which is a trifle lower down aud subpyriform. The hinge-line
and ligament pit are normal.

Length 6|- mm., height 4i.

Habitat. — Stations 187 and 188, Iwth iu the region of Torres Strait, North Australia,
at depths of 6 and 28 fathoms.

This species is even more elongate than Myodora. oblonga, in addition to which it is
more finely ridged and less acutely beaked at the apex. Myodora pandoriformis is also
shorter and more finely microscopically sculptured.

Myodora australica (Reeve).

Thraeia wustralica, Eeeve, Conch. Icon., fig. 1-3.

Tliracia novu-zelandica, Eeeve, Couch. Icon., fig. 19.

Thraeia novo-zelavdien, Hutton, Manual Moll. New Zealand, p. 136.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms (Challenger) ; Moreton Bay
(Reeve) ; Port Jackson (Angas and Voyage of the " Rattlesnake," in the British Museum).

This, like all the species of the genus, is inequivalve and white, and sculptured with
microscopic concentric stride which are interrupted by others radiating irregularly from
the umbones, producing a shagreened surface. It is much longer tlian high, somewhat
trigonal, acuminate anteriorly, and truncated behind. The right valve is moderately
convex and larger than the left, which is much flatter. Both are marked with subplicate
lines of growth, and have a slight arcuate angle running from the beaks to the lower
posterior extremity, behind which the surface is somewhat concave. The front dorsal
margin is elongate, moderately sloping, and very slightly arcuate, the posterior being not
quite so oblique, shorter, a little excavated near the umbones, and then straightish. The
ventral outline is very gently curved, forming a rounded angle at its junction with tlio
posterior side, and joining the anterior dorsal slope in a sharp curve. The umbones are
acute, and the area is lanceolate, excavated, and defined by sfight ridges. The dorsal
margins of the left (flattened) valve are acute, but at right angles to the rest of the
surface, and act as lateral teeth, fitting into corresponding grooves in the other valve.
The ligamental scar beneath the beaks is narrow, rather small, moderately deep, and slopes
a little towards the posterior end. The anterior scar is long and narrow, the hinder one
being shorter and ii-regularly rounded. The sinus in the pallial line is large, deeper than
high, rounded at the end, and not extending to the centre of the valves. The internal

68 THE VOYAGE OF H.M.S. CHALLENGER.

surface is dull, roughish, or minutely subgranulated about the middle, smoother, more
shining, and radiately substriated towards the ventral margin.

Reeve recognised the general outward resemblance of this form to Myodora, and it is
to be regretted that he did not, before describing it, examine the hinge. Had he done
so he would at once have perceived that it did not corres^jond with that of TJiracia, but
in reality was truly Myodoroid. His conjecture that his TJiracia novo-zelandica might
possibly be a variety of Thracia australica is confirmed l;)y the fact that it also proves to
belong to Myodora, and the locality " New Zealand " has yet to be confirmed, for, so far
as at present known with absolute certainty, the species appears to be limited to New
South Wales and Queensland.

Myodora angustata (Angas).

Alicia angustata, Angas, Proc. Zool. Soc. Lond., 1867, p. 908, pi. xliv. fig. L
Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

At present I see no gi-ounds for separating this species and Alicia^ elegantula, Angas,
generically. Both species have the left valve smaller than the right, are white,
truncated posteriorly, and sculptured microscopically as in all the species of Myodora.
The composition of the hinge in both proves to be identical, and the pallial line is
sinuated. The more elongate form and the fact of the left valve l^eing rather moi'e
convex than in most other species are not in my judgment characters of any importance
from a generic point of view.

Subfamily Thraciin.e.

Thracia, Leach.

Thrxicia meridionalis, n. sp. (PI. YI. figs. 4—46).

Testa paulo iusequilateralis, modice convexa, ovato-oblouga, postice truncata, cariuam
obsoletam ab umbonibus ad extremitatem posticam exhiljeus, sordide albida, lineis
incrementi rugosis, striisque tenuibus concentrice seulpta,undique minute grano-scobinata;
margo dorsi antice valde declivis, aliquanto arcuatus, postice brevior, minus descendens,
rectiusculus; margo ventris levis.sime excurvatus, uti'inque parum adscendens. Latus
anticum rotundatum, posticum oblique, vix arcuatim tnmcatum. Cardo, cicatrices et
lallii sinus fere \\t in TJiracia truncata (Brown).

This species is of an oblong form, rounded in front and squarely truncated posteriorly,
slightly inequilateral, the anterior side being a trifle the longer. It is moderately

lis name was previously employed by Mr. .7. Y. Johnson for a remarkable Sea Anemone, Proc. Zool. Soc. Lond.,
03.

REPORT ON THE LAMELLIBRANCHIATA. 69

convex, depressed or a little concave l>elund,a faint angulation extending from the umbones
to the lower posterior end, thin, dirty whitish, finely concentrically striated, marked with
more distinct lines of growth here and there, and everywhere very minutely roughened
or subgranulated. The dorsal line is very oblique and moderately arched anteriorly, less
descending and rectilinear behind, forming with the side margin, which is almost straight,
and slopes inward or towards the middle of the slightly curved lower margin, a rather
sharp angle. The hinge is not quite like that of TJirncla fruncata of Brown, the process
to which the ligament attaches itself lieing rather slighter, distinct from, and soldered to
the hinge-line. The muscular scars and the sinus in the pallial line are similar.

Length 23 mm., height 19, diameter 10.

Length 23 mm., height 18, diameter 9|.

Habitat. — Royal Sound, Kerguelen Island, in 20 to 60 fathoms ; Betsy Cove, in
20 to 25 fathoms ; Marion Island, in 50 to 75 fathoms ; and Prince Edward Island, in
100 to 150 fathoms.

This is the southern representative of the Greenlandic species Thvacia truncata, and
indeed differs so slightly from it that it is with considerable hesitation I venture to
describe it as distinct, being mainly influenced to do so by the difference of locality. It
is not so equilateral, has the ventral margin straighter, the posterior end more abrujitly
truncated, the extremity being at the upper angle, whilst in the boreal form the low^er end
is usually the most prominent. The hinder dorsal slope in the present species is a little
reflexed or bent over in botli valves, forming an indistinct area, which in Thracia truncata
is scarely traceable. A more tangible difterenee is in the slighter shelly process which
supports the ligament, being, as it were, a separate ])iece joined on to the hinge-line.

Tliracia iratsoni, n. sp. (PI. VI. figs. 5—56).

Testa magna, eomplanata, fere, aequilateralis, utrinque dorsaliterque aliquanto hians,
all)ida, concentrice fortiter plicato-rugata, scabra, granulata, transversim oblonga, antice
rotundata, postice obbque truncata, margine ventrali rectiusculo rotundatim in latum
anterius ambiente. Margo dorsi auticus paulo obliquus, vix arcuatus, posticus valvse
dextrse mediocriter concavse horizontalis, in valva sinistra siibplana leviter obliquus, iufi-a
umbonem concaviusculus. Umbones parvi, acutissimi, postice inclinati. Area excavata,
subacute marginata. Ligamentum externum utroque ajMcis latere pi'olongatum, antice in
fossula parva marginam intra situm. Cartilago interna magna, triangularis, in receptaculo
calloso crasso inclusa. Cicatrix muscularis posterior fere circularis, anterior elongata,
irregularis. Pallii sinus profundus, latus, ad apicem rotundatus.

This magnificent large species is much compressed, very elongate, not quite twice as
long as high, almost equilateral, rounded in front, oljliquely truncated at the opposite

70 THE VOYAGE OF H.M.S. CHALLENGER.

extremity, and gapes somewhat at both ends and along the back. It is dirty whitish,
concentrically coarsely plicate -wrinkled, the rugse being stronger upon the central
portion of the valves, becoming more or less obsolete towards the dorsal margin on both
sides. The surface or outer shell-layer is everywhere rough to the touch, minutely
granular, and produced in the left or flat valve beyond the white shelly interior, forming
a broadish buff border composed of a compact tessellation of thousands of the minutest
plates as it were soldered together. The dorsal margin is slightly arcuate on the
anterior side and somewhat oblique, posteriorly being almost rectilinear, and horizontal in
the right or deep valve, but a trifle oltlique and concave near the beak in the left. In
this valve, on both sides of the umbo, it is turned over abruptly, almost at right angles
towards the other valve. The lower outline is straightish along the middle, consideraljly
up-curving in front, and only a little behind, forming with the oblique latter margin a
well-rounded corner. The umbones are small, very acute, not at all inflated, and turn
towards the hinder end. On this side the dorsal area is excavated at the beaks, where it
is rather sharply margined on each side. The external ligament extends on both sides of
the umbones, in front having a narrow short groove partitioned ofl' for its reception.
The internal cartilage is large, equilaterally triangular, located in a strong shelly process
firmly soldered to the valves immediately beneath the beaks, which is unusual. The
muscular scars are high up, the posterior being nearly circular, near the dorsal margin,
and somewhat remote from the end of the shell. The anterior is in about the same
position, elongate, narrow, bent in the middle. The siphonal inflection of the jjaUial line
is deep, broad, rounded at the end, and extends across the valves about five-fourteenths
of the entire length of the shell.

Length 58 mm., height 32, diameter 10.

Habitat. — Station 162, oft' East Moncoeur Island, Bass Strait ; in 38 to 40
fathoms ; sand and shells.

This fine large species is remarkable on account of its flattened compressed char-
acter, and being almost equilateral. The ligament-pit is very strong, and the outer
epidermal shell-layer is peculiar. I have much pleasure in naming it after my friend
the Rev. R. Boog Watson, who is carefully preparing a Report upon the Gasteropoda
and Scaphopoda of the Expedition.

Thracia myodoroides, n. sp. (PI. VI. figs. 6— 6&).

Testa subcompressa, sequilateralis, aliquanto triangularis, postice late truncata, antice
rotunde cuneata, albida, minutissime granulata, incrementi lineis hie illic inconsjiicuis
arata. Margo dorsalis anticus valde obliquus, rectiusculus, vix excurvatus, posticus
leviter declivis, rectilinearis. Yentris margo parum arcuatus, antice lente adseendens, cum
dorsali acuto-rotundatim junctus. Umbones parvi, acuti, latus versus posticum vix

REPORT ON THE LAMELLIBRANCHIATA. 71

iiiclinati. Ligamentum Havum in sulco angusto marginali sitiim. Sinus pallii latus,
arcuatus, havid profiiudus.

This species is ouly slightly inequivalve, equilateral, one-third longer than high,
moderately convex, ii-regularly triangular, narrowed in front and broadly truncated
posteriorly. The valves are white, very finely granulated throughout, exhibit marks of
growth at intervals, and have a rounded angle extending from the umbones to the lower
posterior extremity, and another subparallel with tlie margin which encloses the dorsal
area. The dorsal margin is rectilinear posteriorly and nearly so in front, and almost equally
obliijue on both sides, forming at the apex an angle of about 130°. The anterior end is
rather wedge-shaped and rounded at the extremity, the posterior side being squarely
truncated, forming rounded angles with the dorsal and ventral margins, the latter being
but very little curved and rather more ascending in front than behind. The external
ligament is yellowish, and located in a narrow marginal groove behind the beaks.
The pallial sinus is broad, arcuate, but not deep. The interior is not very glossy and
radiately substriated.

Length 13 mm., height 9|, diameter 5.

Habitat. — Station 162, off East Moncceur Island, Bass Strait, in 38 to 40 fathoms.

This species is rather like Myodora australica, Reeve, in respect of form.

T/iJ-acia modesta, Angas.

Thracia modesta, Angas, Proc. Zool. Soc. Lond, 1867, p. 908, pi xliv. fig. 3.
Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

The left valve of this species is rather shallower than the right. The single valve
obtained by the Challenger has the posterior truncated end rather broader than the
type figured by Angas, and the lower outline less curved.

Periploma, Schumacher.

Feriploma compressa, d'Orbigny.

Periploma compressa, d'Orbigny, Voy. Am^r. Merid., vol. v. p. 514, pi. Ixxviii. figs. 19, 20.

Testa transversim ovata, antice late rotundata, postice angustior, breviter acuminata,
hians, paulo dextrorsum flexa, valde ingequilateralis, subcompressa, sordide, albida aspera,
minute grauulata, incrementi liueis striata. Margo dorsi anticus perelongatus, leviter
arcuatus et declivis, posticus longe brevior, magis obliquus, primo rectiusculus. Margo
ventris late curvatus, postice leviter sinuatus. Umbones parvi, acuti, fissi, circa in i
longitudinis coUocati. Ossiculum cardinis ovatum, costa oblic^ua sufFultum. Pagina
interna submargaritaeea, linea ai-cuata in valva sinistra ab umbone latum posticum versus
radiante notata. Sinus pallii breviter linguiformis ad apicem rotundatus.

72 THE VOYAGE OF H.M.S. CHALLENGER.

This very interesting form is rather compressed, fragile, hroadly ovate, rounded in
front, narrower and somewhat pouting posteriorly. It is very inequilateral, minutely
granulated, striated by concentric lines of growth, dirty whitish, exhibiting traces of a
pale earth-coloured epidermis, which is somewhat reflexed within the valves. The valves
are about equal in size, bent a little to the right at the posterior end, and gape somewhat
at ])oth extremities, especially behind. The front dorsal margin is slightly convex, very
long, and only a little oblique, the posterior being very much .shorter and rather straight
at first, then, descending in a slight curve, joins the obliqi;ely up-curving and .slightly
sinuated ventral margin at an obtuse point, which is most conspicuous in the left valve.
The umbones are small, acute, slit at the apex, and situated at about one-third of the
entire length from the hinder end. The cartilage-receiver is more or less ovate, directed
obliquely towards the anterior ventral edge, and supported liy a shelly ridge. The
transverse free ossicle is moderately thick. The interior of the valves is whitish, a Uttle
pearly, exhibits the concentric lines of growth, and one or more radiating lines from the
beaks down the posterior side, and apparently more conspicuous in the left valve than
the right. The pallial sinus is moderately deep, reaching rather more than one-third
across the valves, and is sharply rounded at the end.

Length 37 mm., height 28, diameter 13.

Habitat. — Station 321, off Monte Video, in 13 fathoms ; mud.

The types described by d'Orbigny were collected a little farther south, near San Bias,
in North Patagonia.

Lyonsia, Turton.

Lyonsia formosa, Jeffreys (PL YI. figs. 3—36).

Lyonsia funnnsa, Jeffreys, Proc. Zool. Soc. LonJ., 1881, p. 93l), [il. Ixx. fig. 1.

Habitat. — Station 8, off Gomera, Canaries, in 620 fathoms ; sandy mud and
shells. (For further distribution, see Jeffreys, loc. cit.)

The Challenger specimen is oblong and somewhat quadrate, having two distinct ridges
radiating from the umbones, one to the ventral margin at a point a little l)ehind the
middle, and the other to the posterior lower extremity, the former being rounded and
subnodose and the latter even, rather acute, and bearing a series of granules rather larger
than those on the rest of the surface. Both ends are gently curved, and the lower
outline is a little sinuated on each side of the subcentral carina. Behind the posterior
keel the valves exhibit about seven slender feeble radiating ridges, each with a row of
granules along the top, which are similar to those upon the carina. Within the valves
there are seven corresponding faint furrows which have a subpunctate appearance.

REPORT ON THE LAMELLIBRANUUIATA. 73

Lyonsiella, M. Sars.
Lyonsiella jeffreysii, n. s^]i. (I'l. XXV. figs. 1-1/^).

Testa tenuis, globosa, inajquilatenilis, aiitice rcctc truucata, postice et iiifonic arcuata,
sordide albida, intus margaritacea, undique minute granulata, lineis gracillimis numerosis
radiantibus instructa, striisque incrementi hie illic sublamellatis oruata. Margo dorsi
anticus brevis, rectus, horizontalis, posticus longior, declivis, vix excurvatus. Lunula
concava, tota in valva dextra. Umbones incurvati, antrorsum versi. Cardo edentulus.
Ligamentum internum, callo parvo sustentutuni.

This species is thin, convex, inequihxteral, a little higher than long, perpendicularly
truncated in front, rounded behind and along the ventral margin. The front dorsal line
is horizoual and straight, and at the termination forms a sharp angle with the anterior
side. The posterior dorsal edge is rather oblique and nearly rectilinear. The valves are
dirty whitish, dull, somewhat pearly within, everywhere finely granuhu', and also sculp-
tured with many (about fifty) fine hair-like raised lines and a few concentric lines of
growth at intervals, distinct and almost lamellar. The umbones are somewhat incurved,
and directed towards the front. The lunule is concave, smooth, extends to the end of
the dorsal margin, and is entirely in the right valve. It projects a little beyond the level
of the rest of the margin of the valve, and fits into a slight emargination in the corre-
sponding part of the left valve. The hinge-line is altogether destitute of teeth, and the
ligament is internal and supported by a small shelly ossicle underneath. The front
adductor scar is high up, just under the front dorsal margin, the posterior one being lower
down, at the end of the dorsal slope.

Length 19 mm., height 20, diameter 14.

Habitat. — Station 106, Mid Atlantic, in 1850 fathoms; Globigerina ooze.

The preserved animal of this fine species appears to agree very closely with the
description of Lyonsiella by Sars in Eemarkable Forms of Animal Life, p. 25.

It has a single branchial plume on each side, no labial palps, and a byssiferous foot.
The anal and branchial siphonal orifices are distinct, the latter being surrounded by papillae.

Lyonsiella 2'xipyrcicea, n. sp. (PI. XXV. figs. 2-21)).

Testa magna, tenuissima, alba, rotunde cordata, globosa, liris filiformibus numerosis
radiantibus ornata, incrementi lineis tenuibus sculpta, epidermide tenuis.sima sordide
albida induta. Umbones prominentes, antemediani, valde incurvati, antrorsum versi.
Linea cardinalis edentula, tenuis. Ligamentum internum, parvum, paulo pone umbones
situm, callo crassiusculo sufFultum. Pagina interna nitida, submargaritacea, radiatim
striata, striis cum liris externis congruentibus.

(ZOOL. CHALL. F.XP. — PART XXXV. 188.5.) Mill 10

74 THE VOYAGE OF H.M.S. CHALLENGER.

This fiue species is excessively thin, globose, roundly heart-shaped, inequilateral,
transparent wliite, but rendered rather opaque by a thin dirty-white epidermis. The
sculpture consists of numerous (about forty) very slender hair-like lines, which radiate
from the beaks to the outer margin. They are fairly equidistant, and cover the whole
surface with the exception of a small space in front of the umbones. The valves are also
very finely striated by the lines of gi'owth, a few at intervals, which apparently mark
periods of arrested enlargement, being quite conspicuous. The umbones are large,
prominent, well incurved, situated considerably in front of the centre, and inclined over
towards the anterior side. The hinge-margin is very thin, and absolutely toothless.
The principal ligament is short, entirely internal, attached under the dorsal margin a
little behind the umbones, and supported or strengthened underneath by a rather strong
callosity, which is rounded beneath, and deeply notched at the hinder end. In addition
the valves are connected by a thin ligament along the hinder dorsal edge. The interior
of the valves is glossy, somewhat pearly, and feebly radiately grooved, the fine striae
corresponding with the external lirse.

Length 23 mm., height 24, diameter 16.

Habitat. — Station 157, about 1100 miles south-west of Australia, in 1950 fathoms;
Diatom ooze.

Of this fine species only a single much crushed specimen was obtained. It differs from
Lyonsiella Jeffrey sii, with which it agrees in the character of the hinge and ligament, in
form and in wanting the fine granulation on the surface.

Lyonsiella grandis, n. sp. (PI. XXV. figs. 3-36).

Testa tenuis, inflata, valde injequilateralis, alba, epidermide tenuissima pallide straminea
plus minusve induta, liris filiformibus radiantibus crebris ornata, incremeutique lineis
subcancellata. Margo dorsi anticus brevissimus, posticus paulo declivis, I'ectus. Margo
ventral is semicircularis, postice oblique in latus arcuatim ambiens. Latus anticum
obliquum, in medio rectiusculum, utrinque rotundatum. Umbones magui, pileiformes,
jirominentes, conspicue latus versus anticum iuvoluti. Cardo edentulus. Ligament!
sulcus interni angustissimus, brevis. Cicatrix antei'ior formse elongatse irregularis infra
umbones sita, posterior major prope medium latevis. Impressiones du« minores infra
lineam cardinis collocatse.

This species is very thin, considerably inflated, very inequilateral, higher than long,
white beneath a somewhat thin pale yellowish epidermis. The valves are very finely and
closely radiately Urate, and exhibit rather distinct, elevated lines of growth which almost
produce a cancellated appearance.

The umbones are inflated, prominent, cap-shaped, much curved over towards the fi'ont.

REPORT ON THE LAMELLIBRANCHIATA. 75

having the apices rolled up remote from one anotlier and the hinge-line, and situated quiti-
near the anterior end. The posterior dorsal margin is rather straight, onl}'' a trifle
oblique, and joins the broadly arcuate lateral outline in a well-rounded curve. The
anterior portion of the upper mai-gin is very short, forming merely a rounded angle with
the obliquely truncate, almost rectilinear, anterior side. The ventral outline is semicircu-
larly curved, and more gently ascending posteriorly than in front. The interior is white,
glossy, and apparently more or less iridescent. The anterior muscular impression is
elongate, of an irregular form and high up, just beneath the umbones. Behind there are
three impressions, one (the largest of all) is situated about the middle of the posterior side,
the two others being under the dorsal margin. The hinge-line is simple and toothless,
having a thin external ligament attached to the edge along nearly the whole extent. The
internal Ligament is very slender, located in a very narrow groove, near, but within tlic
edge, and probably supported by a free ossicle.

Length 14 mm., height 16, diameter 12.

Habitat. — Station 133, Mid South Atlantic, in 1900 fathoms; Globigerina ooze.

Only a single dead specimen of this fine species was obtained. It differs from
Lyonsiella papyracea, not only in form and smaller size, but also in having much more
numerous lirse.

Silenia, n. gen.

Testa tenuis, ovato-oblonga, iutus margaritacea, concentrice striata, sparsini
granulata; cardo edentulus ; ligamentum externum, marginale. Animal ovato-oblongum,
convexiusculum ; pallium inferne apertum, postice siphones infra clausum. Apertura
siphonalis papillis elongatis couicis scabris circumdata ; sipho branchialis magnus, externe
hand prominens, intus in tulja magna productus, anali contra minimo, externe paulo
exstanti, intus baud prolongate ; pes parvus, gracilis, sulco byssali baud aratus. Papillae
oi'ales inajquales ; anticse permagnse, posticse parvse. Branchite insignes, utrinque in s(M"ie
interrupta, posticeque serie altera transversa etiam in medio interrupta digestae.

This remarkable form differs from Lyonsiella in possessing well-developed labial palpi,
in the character and disposition of the branchiae, and one or two points with regard to the
siphonal opening and the foot, &c. The shell may be distinguished from that of Lyonsiella
by the difference in the hinge-characters, the latter genus having an internal ligament
supported by a free ossicle, whilst in Silenia it is external and without a shelly support.

Sileriia sarsii, n. sp. (PL XXV. figs. 4-46).

Habitat. — Station 157, about 1100 miles south-west of Australia, in 1950 fathoms;
Diatom ooze; also Station 325, east of the mouth of the Rio de la Plata, in 2650 fathoms:
blue mud.

76 THB VOYAGE OF H.M.S. CHALLENGER.

The soft parts of two specimens and a few fragments of the shells adhering to
them were alone obtained. From these it is evident that the species is rather large,
probably about 20 mm. in length. The shell is excessively thin, prettily iridescent
within and faintly so on the outside, which is more or less covered with a thin filmy pah;
yellow epidermis, which towards the outer margin of the valves is produced into oldiquc
thread-like lines, and somewhat reflexed within. The sculpture consists of distinct
concentric lines of growth, a few subdistant hair-like radiating lines chiefly observable
near the outer mai'gin, and very minute rather irregularly scattered granules which
appear to be most numerous and more i-egularly arranged on the anterior side. The
umbones are white, smooth, incurved, and incline towards the front. The hinge-line is
rounded and quite toothless in both valves. The ligament is external, strongish, and
attached to the edge of the valves.

I cannot discover any sufficient reasons for separating the Australian and American
specimens of this very interesting species. They agree exactly as regards the hinge, the
fragility of the valves, the epidermis, and the character of the sculpture, the Atlantic
example, however, exhibiting rather more distinct granulation. The animals also are
precisely alike, even the number of papillas surrounding the siphonal openings being
precisely the same, namely fifteen. This is another instance of the remarkable distribu-
tion of some deep-sea forms.

Suljfamily Anatinin^.

Anatina, Lamarck.
Anatina siphonafa, Reeve.

Anatina siphonafa, Keeve, Conch. Icon., vol. xiv. pi. i. tig. 2.
Habitat. — Station 208, Philippine Islands, at a depth of 18 fathoms ; l>lue mud.

The Challenger specimen is a little larger than the ty[:)e, and almost exactly of the
same form. I think it probable that Anatina Jiexuosa, Reeve, Anatina cumingii,
Valenciennes, Anatina amphora, Reeve, and one or two other so-called species, together
with that under consideration, are merely variations of one and the same form.

Anatina elliptica (King and Broderip), juv.

Anatina elliptica, King and Broderip, Zool. Journ., vol. v. p. 3.3.5.
Anatina dliptica. Reeve, Conch. Icon., vol. xiv. fig. 14.
Anatina elliptica, Griffith's Anim. Kingd., vol. xii. pi. xxii. fig. 3.
Anatina prismatica, Sowerby, Proc. Zool. Soc. Lond., 1834, p. 87.

Testa juvenis fragilissima, oblonga, transversa, antice rotuudata, postice lata, arcuatim
truncata, inasquilateralis, alba, concentrice rugose striata, sulco obliquo baud profundo ab

KEPORT ON THE LAMELLJBRANC}II AIA. 77

umlionibus ii.s(jue ml cxtrcmitatem iuferioicni postieam arata, radio parum elevato
iimboues infra subperpeudiculari interdum vix conspicuo instructa. JVIargo dorsi anticus
obliquus, leviter arcuatus, posticus longior, liorizoutalis, prope umbones concavus.
Ventris marge rectiusculus. Latus antieum l)revis, subacute rotundatum, vix hians,
posticum latum, apertissimum. Umbones parvi, acuti, ante medium siti. Cartilage
interna inter callos duos minutos posita ; pagina interna uitida, plus minusve prismatica,
superne infra umbones porca obli(|ua gracili, tubcrculo juncta, margine minute dentate
instructa.

This shell is oblong, half as long again as high, very thin and fragile, semitransparent
white, concentrically rather coarsely wrinkled and striated, exhibiting on each valve a
shallow groove radiating from the umbones to the lower posterior extremity, and towards
the front having (but not always) a faintly elevated ray, which falls almost perpendicularly
beneath the beaks to the ventral margin. It is rather inequilateral, much gaping, broad
and arcuately truncated posteriorly, uarrow^ed and somew^hat sharply curved in front, and
straightish along the lower outline. The anterior dorsal slope is obliquely descending
and faintly convex, the posterior being a little concave near the beaks, and then
horizontal or even a trifle ascendant. The umbones are small, acute, and h cated
rather in front of the centre. The hinge-cartilage is placed between two minute
shelly processes from which diverge in an oblique dii'ection towards the hinder extremity
of each valve a slender elevated ridge, the edge of which, under the microscope, is
seen to be minutely serrated or dentate. The muscular scars and mantle-impression are
indistinct.

Length 12 mm., height 8, diameter 5.

Habitat. — Betsy Cove, Kerguelen Island, in 15 to 25 fathoms, January 9, 1874 ;
and Eoyal Sound, Kerguelen Island, in 28 fathoms.

A specimen of this species, more than two inches in length, was collected at Cumber-
hind Bay, Kerguelen Island, during Captain Eoss' voyage, and is now in the British
jMuseum. In the same collection are two or three others from New South Shetland,
(me presented by Captain P. P. King, E.N., being the type described by himself in
conjunction with Mr. Broderip. In the adult shell, which is rather solid and beautifully
pearly under the external calcareous surface, the internal septum loses its denticulate
character.

The muscular scars are high up near the dorsal margin, both being ef an elongate
form. The sinus in the pallial line is very wide, and varies somewhat in depth in
different specimens. The adult shells show considerable variation in the relative length
of the two sides. Some specimens are almost equilateral, whilst others have the anterior
portion longer than the posterior, the reverse l)eing the case with the young individuals.
The figure given by Eeeve gives a i-ather unusual up-curving of the hinder dorsal margin,

78 THE VOYAGE OF H.M.S. CHALLENGEK.

and represents a shell somewhat higher than usual. The epidermis, judging from thf^
slight remains on this specimen, is rather thick and fibrous.

Family S A x i c a v i d .e.

Saxicava, Fleuriau de Bellevue.

Saxicava arctica, Linn^.

Habitat. — Station 75, oiF Faj'al, Azores, in 500 fathoms. Station 313, Strait of
Magellan, in 55 fathoms; off Nightingale Island, Mid South Atlantic, in 100 to 150
fathoms. Stations 141 and 142, off the Cape of Good Hope, in 100 to 150 fathoms;
Marion Island, in 100 fathoms; Prince Edward Island, in 150 fathoms. Station 150,
south of Kerguelen, in 150 fathoms. Station 311, West Patagonia, in 245 fathoms ; and
lastly, at Port Jackson, Sydney, in 2 to 10 fathoms.

This polymorphous species, judging from the shells alone, is apparently distributed all
over the globe. Of the animals inhabiting them we know nothing except those of northern
varieties. The shells vary immensely in form, thickness, and ornamentation. Those
found off the South African coast are especially remarkable for the great development of
the spines on the posterior side, and have been raised to specific rank by Mr. Sowerby
(Conch. Icon., vol. xx. fig. 12) under the name of Saxicava spinifera. Many localities
have already been cited for this species, and among them may be mentioned Greenland,
Norway, Great Britain, Sitka, Japan, California, Peru, Patagonia. Canaries, Madeira,
Mogador, Mediterranean, Madagascar, Cape of Good Hope, Australia. New Zealand, &c.;
and it is also found fossil in several Upper Tertiary formations.

Family S o l e n i d .e.
Solen, Linne.
Solen sloanii, Gray.

Solen sloanii, Gray, MS. Brit. Mus.

Solen sloanii, Hanley, Cat. Biv. Shells, 1843, jjp. 12 and 336, pL xi. fig. 18.

Sole^i sloanii, Angas, Proc. Zool. Soc. Lond., 1867, p. 912.

Solen sloanii, Sowerby, Conch. Icon., vol xix. pi. iii. fig. 10.

Solen versicolor, Philippi, Abbild., vol. iii. p. 43, pi. ii. fig. 3.

Solen pMHjtpianus, Dunker, MS. in Mus. Cuming.

Solen philippiamis, Sowerby, loc. at, fig. 13.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

REPORT ON THE LAMELLIBRANCHIATA. 79

I have been unable to discover any description by Dunker of Solen philippianus,
no mention of it being made in the Proc. Zooh Soc. Lond. for 1861 as stated by
Sowerbv.

SolecuTtu-'i, Blainville.

Solecurtus (^20?') coarctatus (Gmelin).

Solen roarctatus, Gmelin, Syst. Nat., p. 3227.

Solen angusfior, &c., Cliemiutz, Concli.-Cab., vol. -vi. p. 62, pi. vi. fig. 4.5.

Solecurtus ahbreviatus, Gould, Proc. Bost. Soc. Nat. Hist., 1861, vol. viii. p. 26; Otia, p. 164.

Solecurtus abbreviatus, Sowerby, Concli. Icon., voL xix. figs. 6a-b.

Macha abbreviatus, Conrad, Amer. Journ. Conch., vol. iii., Appendix, p. 23.

Macha schcejmiakeri, Dunker, Zeitscli. f. Mai., 1852, p. 56.

Azor (Macha) scheepmaJieri, Dimker, Novitat. Conch., p. 121, pi. xxxix. figs. 10, 11.

Solecurtus scheepmalteri, Sowerby, loc. cit., pi. iii. fig. 14.

Azor oblongiis, Dunker, Proc. Zool. Soc. Lond., 18G1, p. 425.

Solecurtus oblongus (Dohrn), Sowerby, loc. cit., fig. 2.

Azor solidus, Dunker, Proc. Zool. Soc. Lond., 1861, p. 425.

Solecuiius solidus (non Gray), Sowerby, loc. cit., fig. 3.

Habitat. — Station 188, south of New C4uinea, in 28 fathoms; mud.

This species may be known l^y the de^aressed ray, which descends obHc[uely across
the middle of the valves. In this respect it differs from the European Solecurtus anti-
quatus, and it is also more inequilateral. Chemnitz, in his description, remarks upon
this depression, and it is strongly depicted in his figure. On this account, and also for
the reason that his specimen came from the Nicobar Islands, I am inclined to agree with
Jeffreys in considering this distinct from the British Solecurtus antiquatus. All the forms
above mentioned agree in having the radiating groove, a similar epidermis, &c., and
differ only slightly in form. Solecurtus ahbreviatus was described from Chinese examples,
Solecurtus solulus, Solecurtus ■■icheepmakeri, and Solecurtus oblongus being quoted as
Philippine forms. Sowerby (Conch. Icon., fig. 3) represents the type shell described
by Dunker as Azor solidus, but refers the species to the Solen solidus of Gray. If Mr.
Sowerby had read the description in the Spicilegia Zoologica, p. 7, pi. iii. fig. 12, he
could not have made such an unpardonable mistake. Gray's shell has been figured by
Reeve in his monograph of the genus Psammohia, pi. iii. fig. 18, as a manuscript species,
he not being aware of its description having been published many years previously :
and it is a curious coincidence that this same species w-as subsequently described and
figured by Philippi as a Psammohia (Abbild., vol. i. pt. 4, p. 1, pi. i. fig. 1) under the
siime specific name (solida) employed originally by Gray.

80 THE VOYAGE OF H.M.S. CHALLENGER.

Family P A p h 1 1 d ^.
ErvUia, Turton.

Evvllia castanea (Montagu).

Donax castanea, Montagu, Test. Brit., part ii. p. 573 ; Supiil., pi. xvii. fig. 2.
ErvUia castanea, Forbes and Hanley, Brit. Moll., vol. i. p. 341, pi. xxxi. figs. .5, 6.
Krrilia castanea, H. & A. Adams, Gi'neia Moll., vol. iii. pi. cvi. figs. 7, 7a.

Amphidesma castanen, Je(fre3's, Brit. Conch., vol. ii. p. 413; vol. v. pi. xliiL fig. 1 ; Proc. Zool.
Soc. Lond., 1881, p. 922.

Hahitaf. — Stations 75 and 78, off the Azore.s, in 450 and 1000 fathoms ; also off
Tenerife, in 70 fathoms.

For the distribution of this species, vide Jeffrey's paper in the Proc. Zool. Soc. Lond.

The West Indian Enjcina nttens, Montagu, is very like this species, and is mainly
distinguished by its rather coarser concentric sculpture and different colouring. The
composition of the hinge is identical.

Ervilia hlsculpta, Gould.

Ei-vilia hisadjila, Gould, Proc. Best. Soc. Nat. Hist, 18G1, vol. viii. p. 28 ; Otia, p. 1G6.
Erivlia australis, Angas, Proc. Zool. Soc. Lond., 1877, p. 17.5, pi. xxvi. fig. 21.
Ervilia incolor, DosLayes, MRS. iu Brit. JIus.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms (Challenger and Angas) ;
off the Pteefs at Honolulu, Sand^^^ch Islands (Challenger) ; Kagosima, Japan (Gould) ;
Island of Samar, Philippines (Mus. Brit.).

Australian specimens of this species appear to be rather more finely concentrically
striated than those from Japan, judging from a single examjsle in Cuming's collection
from that locality. Although Gould refers only to radiating sculpture on one side, I find
it occurring on both, in all specimens.

Ervilia sitbcancellata, n. sp. (PL VI. figs. 2-2?^).

Testa subtrigona, acuminate ovata, snbtennis, parva, alba vel roseo tincta, 2"/auk)
insequilateralis, concentrice tenuiter lirata, liris ad latera atteuuatis, striis tenuibus
radiantibus postice decussatis. Margo dorsi posticus elongatus, fere rectilinearis leviter
declivis, anticus brevior, vix excurvatus et obliquus. Umbones parvi, parum prominentes,
sul)acuti, apicibus postice versis, paulo ante medium coUocati. Cardo ut in Ervilia
castanea.

This species is considerably longer than high, triangularly oval, not very thin, white
or stained with rose, chiefly on the posterior portion. It is a little inequilateral,

REPORT ON THE LAMELLIBRANCHIATA. 81

moderately convex, and sculptured with fine concentric lirse, which become more slender
at the sides, and are crossed chiefly on the hinder part by fine radiating striae. The
dorsal mai-gin is angled at the beaks, and descends about equally on both sides, the
posterior portion, however, being rather longer than the anterior. The ventral outline is
broadly arcuate, about equally ascendant on each side, and forms, together with the dorsal
slope, acutely rounded extremities at both ends. The beaks are not much elevated, small,
moderately acute, and curved over at the tip towards the hinder end. The hinge consists
of a central large triangular cartilage-pit in both valves, which in the right is bordered
in front with an erect oblique prominent tooth fitting into a corresponding deep groove
in front of the cartilage-pit in the left valve. The anterior of the valves has a short
ridge or thickening, which, arising beneath the umbones, descends to the inner side of the
anterior muscular impression.

Length 5 mm., height 3|, diameter 2.

Habitat. — Station 33, off Bermuda, in 435 fathoms; coral mud. Station 113a,
off Fernando Noronha, in 25 fathoms ; and Station 120, ofl" Pernambuco, in G75 fathoms.

This species is very like Ervilia nitens, but apparently does not attain such large
dimensions. It is more finely concentrically striated and prettily cancellated down the
posterior side. In some instances, however, the radiating striaB extend more or less over
the entire surface. There are specimens in the British Museum from St. Thomas and
St. Vincent in the West Indies.

Ervilia sandwichensis, n. sp. (PL XXV. figs. 5-56).

Testa infe(]^uilateralis, compressiuscula, ovata, all^a, liris concentricis tenuibus aliisque
radiantibus concinne granoso-cancellata. Margo dorsi posticus leviter declivis,
rectiusculus vel levissime arcuatus, anticus longior, prope umbones j)eculiares tubercu-
liformes et rufescentes paulo concavus. Latera sequaliter subacute rotundata ; margo
ventris late arcuatus.

This species is pure white, with the exception of the minute tuberculiform embryonic
tips of the umbones, which are of a reddish tint. It is transversely ovate, equally and
rather sharply rounded at the sides, and broadly curved beneath. It is somewhat
compressed and inequilateral, and sculptured with numerous slender concentric lirae, and
others which radiate from the beaks, forming a very pretty cancellated surface, as the
points of intersection are more or less nodulose.

The structure of .the hinge is normal as in Ervilia castanea. The interior is very
glossy, and, owing to the transparency of the shell's texture, the external ornamentation
is visible.

Length 3 mm., hieght 2, diameter \\.

Habitat — Off the Reefs at Honolulu, Sandwich Islands, in 40 fathoms.

(ZOOL. CHALL. EXP. — PART XXXV. 1885.) Mill 11

82 THE VOYAGE OF H.M.S. CHALLENGER.

Only a single minute valve of this species is at present known, which probably does
not nearly approach the full size it attains in a more adult condition. Considering the
distinct character of the sculpture, and that it is very different from all the known species,
I have thought it advisable to describe this species although represented by such slight
material.

Davila, Gray.

Davila (?*) umbonata, n. sp. (PI. VI. figs. 1-1^).

Testa transversim ovalis, mediocriter insequilateralis, albida, polita, incrementi lineis
concentricis irregularibus sculpta. Umbones alti, product!, ad apicem erosi. Latus
anticum breve, acute rotundatum, posticum longius, latius curvatum. Margo dorsahs
anterior levissime arcuatus, valcle obliquus, posterior minus descendens, subrectilinearis,
ventralis late arcuatus. Dentes cardinales tres in utraque valva, cjuorum duo ante liga-
meutum siti sunt. In valva dextra anterior gracilis, prope marginem locatus, in sinistra
medianus minimus. Impressioues musculares irregulares, antica minore. Linea pallii
postice vix siuuata. Cartilage interna magna, fusca. Ligamentum aliud linearis infra
umbones situm.

The shell is thinnish, white, glossy, and striated by fine lines of growth, at intervals
some of the strise being deeper than the rest, as if marking off periods of growth. In
front a large lunule is marked off by a faint line not seen by the naked eye. The form is
nearly transversely oval, except that the dorsal outline is interrupted by the beaks, which
are situated a little excentrically and rather nearer the anterior side. They are eroded at
the tips, a trifle prominent alcove the hinge-line, and scarcely turned towards the front.
The hinge is composed of three unequal and divergent teeth in each valve, a largish
internal cartilage having two of the teeth in front and the third posterior to it, and in
addition a linear ligament along the dorsal edge immediately under and on both sides of
the tips of the umbones. In the right valve the foremost tooth is slender, close to and
parallel with the outer edge of the valve. The second or median tooth is also slender,
a trifle larger than the anterior, from which it diverges somewhat, yet having a forward
direction. The hindmost, likewise narrow, inclines backwards, and is separated from the
outer edge by a deepish groove. In the left valve the anterior tooth is decidedly the
largest, separated from the margin with which it is subparallel by a deepish furrow.
The posterior is somewhat smaller, prominent, and close to the outer edges, and the
median one is very small, just under the umbo, and scarcely rises to the level of the
dorsal margin. The interior of the valves is glossy and white. The muscular impressions
are subequal in size and rather irregular in outline. The pallial line is rather remote
from the ventral margin, and exhibits the slightest indication of a j)osterior sinus or
emargination.

REPORT ON THE LAMELLIBRANCHIATA. 83

Length G^ mm., height nearly 5, diameter 3|,

Habitat. — Off Royal Sound, Kerguelen Island, depth 25 fatlioms; also Prince
Edward Island, 150 fathoms, and j\Iarion Island, 100 fathoms.

Variety. — This form is more compressed than the type, thinner, higher in proportion
to the length, with smaller, less inflated, non-eroded beaks, and the line cu'cumscribing
the lunule is less distinct.

Length 7 mm., height 5f, diameter 3.

Habitat. — Balfour Bay, Royal Sound, Kerguelen, in 20 to 60 fathoms.

The specimens from Prince Edward and Marion Islands, which, I believe, belong to
this species, ax-e all young, and in this state do not exhibit any trace of a lunule.

This species does not quite correspond in the hinge with the t}ijical form of Davila,
Davila 2^lci>ia of Hauley having in the left valve a small, anterior, lateral tooth, which
is absent in Davila iimbonata. The very insignificant emargination of tlie pallial line i."^
equally apparent in both.

Family S c R 0 B I G-u L A R 1 1 D ^.

Subfamily Semelik.e.

Semele, Schumacher.
Semele amabilis, A. Adams.

Semele amahilis, A. AJams, Proc. Zool. Soc. Lond., 18.53, p. 97.
Amphidesma amabilis. Reeve, Conch. Icon., vol. viii. pi. v. fig. 32.

Habitat. — Station 189, Arafura Sea, in 25 to 29 fathoms, green mud (Challenger);
Port Curtis (A. Adams).

This is a very elegant shell, and remarkable on account of the thin elevated and uji-
turned concentric lamellae which adorn the surface. It is somewhat longer than high,
moderately compressed, almost equilateral, white and stained with brown down the
posterior side of the left valve. The front dorsal slope is somewhat concave near the
umbones, then oblique and straightish, the posterior being a little arched and scarcely so
sloping. The ventral margin is regularly curved, and forms in front, together with the
dorsal edge, a broadly rounded end. The hinder extremity is more irregular, termin-
ating in an obtuse angle, and exhibiting more or less of an oblique truncation below the
angle. The two valves are not similar at the posterior part. In the left there is a
single broadish depression radiating from the beak, subparallel with and only a short
distance from the hinder dorsal marijin, causing a flexure in the concentric lamellae. In
the right valve there are two such depressions and a corresponding double sinuosity of
the lamellae. The lunular depression is pretty deeply lanceolate, and the hinder dorsal area
is also narrow, sunken, and defined by carinate edges. The sculpture consi.sts of the remark-

84 THE VOYAGE OF H.M.S. CHALLENGER.

able concentric lamellse which are peculiarly curled upwards, strongly Urate, and minutely
cancellated on the lower side. In addition to these lamellae there are finer concentric lirse
between, usually one in each interstice. Beside these the whole surface is densely and
minutely sculptured with microscopic radiating thread-like lines, which are not so
apparent as those upon the lamellae. The hinge is composed of two minute cardinal teeth
in each valve and two moderately developed laterals, whereof the posterior is rather more
remote from the apex of the umbones than the anterior. The internal cartilage is long
and narrow, and the external ligament, which is somewhat shorter, is slight. The interior
of the valves is white, and exhibits a number of faint radiating depressions, one of them,
which crosses the anterior muscular scar, and is, as it were, a continuatioli of the pallial
line, being particularly noticeable. The pallial sinus is directed upwards, obtuse at the
extremity, and reaches about half-way across the valves. The specimen obtained by the
Challenger is rather larger than the type described by A. Adams, being 66 mm. long,
52 high, and 25 in diameter.

Semele ohliqua (Wood), juv.

Tellina ohliqua, Wood, Gen. Conch., p. 152, pi. xli. figs. 4, 5.
Amphklesma ohliqua, Eeeve, Conch. Icon., vol. viii. pi. i. figs. 5a-h.
Amphidesma variegata, Lamarck, Anim. s. Vert., ed. 2, vol. vi. p. 126.
Davila variegata, Clieuu, Man. Conch., vol. ii. p. 80, fig. 346.

Habitat. — Station 122, off Pernambuco, Brazil, in 350 fathoms; red mud.

Only a single young specimen half an inch in length was obtained. It is whitish,
Ijlotched on the dorsal margin and towards the beaks with pinkish-red, and speckled in
the same region with opaque white. The great depth at which this shell lived probably
will account for the paleness of its colouring, which is much more vivid in all the other
specimens that I have seen.

Semele infans, n. sp. (PI. V. figs. l-\h).

Testa parva, oblique rotundato-subtrigonalis, ina^quilateralis, alba, nitida, iucrementi
lineis sculpta, lunula distincta, lanceolata antice instructa. Umbones acuti, post medium
siti, anticam partem versus inclinati. Margo dorsalis posticus valde descendens, arcuatus,
anterior prope umbones concaviusculus, deinde excurvatus, ventralis late rotundatus,
postice subsinuatus. Dentes cardinales duo iu valva dextra, uuus in valva altera. Fossae
laterales valvae dextrae magnae, latae, usque ad umbonem utrinque extensEe.

The shell is minute, longer than high, thin, glossy, and sculptured with fine yet
distinct lines of growth. It is of a roundish subtriangular form and inequilateral, the
anterior end being the longer and regularly sharply curved, whilst tlie opposite side

REPORT ON THE LAMELLIBRANCHIATA. 85

terminates in a much more acute extremity, and indeed might be described as subrostrate.
The posterior slope descends rather suddenly, and is only a little arcuate, the front margin
being less oblique and more excurved, except in the lunula r region, where it is slightly
concave. The ventral outline is regularly and widely curved except near the liimlcr end,
where it is feebly sinuated, which gives the subrostrate appearance to that portion of the
shell. The lunule is lanceolate, narrow, and bounded by a raised ridge on each side.
There is but a single cardinal tooth in the left valve, about equal in size to either of the
two in the right valve, which are divergent and united at their upper extremities. The
anterior does not stand separated, but is united to the ridge which forms the inner side
of the lateral groove. Those on l)oth sides commence at the beaks, extend a considerable
way down the dorsal margin, and are wide and deep, receiving the i^rominent
corresponding margins of the left valve. The internal ligament is elongate, narrow, and
posterior to the cardinal teeth. The muscular scars and pallial impression are not
clearly definable owing to the condition of the interior of the valves. The posterior of
the former appears to be pyriform, rather large, and broader than the front one. The
sinus in the mantle line is probably large.

Length 3f mm., height 3, diameter 1^.

Habitat. — Flinders Passage, north of Cape York, North Australia, at a depth of
7 fathoms.

The line on each side parallel with the dorsal margin shown in fig. 1 is merely the
inner edge of the hinge-plate, which is visible externally owing to the transparency of the
shell

Semele [Ahra) braziliensis, n. sp. (PI. V. figs. 2-26).

Testa sequilateralis, compressa, tenuis, alba, pellucida, concentrice exiliter striata,
nitida, transversim elongata, postice acuminata, antice latior, rotundata. Margo
dorsalis utrinque fere rectilinearis, pone obliquior quam ante. Area elongata, planata.
Umbones centrales, parvi, acuti. Lunula angusta, baud profunda. Dentes cardinales
valvse dextrse subsequales, divergentes, superne conjunct!. Fossae laterales angustse,
postica ad umbonem baud pertingens. Ligamentum internum valde obliquuni,
angustum. Sinus pallii profundus, ad extremitatem subacutus.

The shell is very thin and fragile, transparent, equivalve, flattened, glossy, striated
with very fine lines of growth, and sculptured with microscopical longitudinal stria?
not visible under a simple lens. The form is transversely elongate, broad and rounded
in front, and wedge-shaped posteriorly. ' The dorsal margin is peculiarly rectilinear on
both sides of the beaks, a little more oblique behind than anteriorly. On the former side
there is a narrow flat dorsal area reflexcd almost at right angles to the rest of the

8G THE VOYAGE OF H.M.S. CHALLENGER.

valve's surface, and consequently bounded by an acute edge extending from the umbo
almost to the posterior extremity of the shell. In front there is a shallow elongate
lunule, but not strongly defined. The umboncs are small, acute, and just prominent
above the hinge-line. The two cardinal teeth in the right valve are about equal in size,
diverge from one another, being united at the upper extremities. The anterior slopes
towards the front, and the posterior in the opposite direction. The lateral grooves for
the reception of the side teeth in the left valve are rather remote from the apex, and the
posterior one does not extend to the umbo, being interrupted by the margin which
borders the internal ligament. This is narrow, elongate, and placed in a very oblique,
deep pit, subparallel with the posterior slope. The adductor scars are somewhat pyriform,
the hinder one being the broader. The siphonal inflection is very deep, extending some
distance beyond the middle of the valve, and is rather acuminate at the anterior
extremity. The interior is glossy and indistinctly radiately substriated.

Length 15^ mm., height 9 J, diameter about 4.
• Habitat. — Station 122, off Pernambuco, Brazil, at a depth of 350 fathoms ; red mud.

This is a more compressed species than Scmele (Abra) lohiUppinensis, with straighter
dorsal margins, and at once distinguished by the flat posterior area.

Semele (Abra) philippinensis, n. sp. (PI. V. figs. 3-3(i).

Testa tenuis, subdiaphana albida, zonis pellucidis hie illic oruata, concentrice tenuiter
striata, subsequilateralis, transversim elongata, antice rotundata, postice valde acuminata,
utrinque angustissime hians. Lunula angusta, lanceolata, baud profunda. Valvarum
pagina interna laevigata, superue prope umbones minute corrugata. Sinus pallii latus,
profundissimus. Dentes cardinales valvse dextrse duo insequales, sinistrse tantum unus,
laterales pi'ominentes, ab apicibus modice remoti.

This shell is transversely elongated, more than one and a half times as long as high,
sharply rounded in front, and acuminate posteriorly. It is thin, somewhat gaping at
each end, not very compressed, semitransparent, glossj^ ornamented with alternate
opaque and diaphanous concentriczones, the former being the broader, and sculptured
with very fine lines of growth. The dorsal outline is sul)rectilinear posteriori}^, and
obliquely descending, in front being all but horizontal, feebly concave close to the beaks
in the region of a small lanceolate lunule, and then faintly arcuate. The ventral margin
is very broadly curved, and more ascending at the anterior than the opposite extremity.
The umbones are small, a little post-median, but slightly elevated, and turned very slightly
towards the front, and are nearly in contact. The two cardinal teeth in the right valve
are unequal in size, diverging, and situated in front of the narrow and very oblique

REPORT ON THE LAMELLIBRANCHIATA. 87

iuternal ligament. The anterior is narrow, and diverges slightly towards the front, the
posterior being twice as thick, triangular, and directed towards the opposite end. The
lateral grooves are broad and deep for the reception of the raised corresponding teeth
in the opposite valve. In this there is but a single cardinal, equalling in stoutness the
large one in the right valve, and fitting in between it and the smaller one. The inner
surface of the valves is glossy in the main, but towards the upper part it becomes dulled
and roughened by a minute corrugation, granulation, and pitting. The muscular impres-
sions are not clearly distinguishable, but ajipear to be moderately large. The siphonal
inflection is very broad and deep, reaching far beyond the centre of the valves.

Length 16f mm., height 10, diameter 5.

Habitat. — Station 210, east of the Island of Panay, Philippine Islands, at a depth of
375 fathoms ; blue mud.

Semele (Abra) regularis, n. sp. (PI. V. figs. 4-46).

Testa elougato-ovata, tenuissima, pellucida, polita, vitrea, paulo insequilateralis,
aUquanto convexa, utrinque acute rotundata, striis tenuissimis concentricis sculpta.
Umbones parvi, paululum supra margincm dorsalem exerti, paulo pone medium collocati.
Margo dorsi leviter convexus et declivis ; ventralis late regulariterque arcuatus. Dentes
laterales valvse dextrae, elongati, lamellares, ab apice fere sequidistantes. Cardinales duo
divergentes, iufequales, postico majori triangulare. Fossa ligament! angusta, elongata,
profunda. Sinus pallii profuudissimus, antice late rotundatus.

Of this fragile shell only a single right valve was dredged. It is excessively thin,
semitransparent, glossy, and sculptured with extremely fine lines of growi;h. It
idso exhibits towards the ventral margin a few short radiating striae, which, however,
may be merely accidental scratches. It is of an elongate ovate form, acutely rounded at
both ends, rather convex, somewhat inequilateral, the anterior side being rather longer
than the posterior. The dorsal margin is gently convex on both sides and moderately
sloping, the ventral being broadly and regularly curved. The beaks are small, a little
post-median, and slightly raised above the hinge-line. The two cardinal teeth of the
right valve are of unequal size, diverging, the posterior being nearly twice the size of the
front one, stout and triangular. The laterals are long, slender, prominent, about equi-
distant from the apex, and separated from the outer edge by a deep groove. The cartilage-
pit is very long, deep, and narrow. The paUial sinus is likewise very deep, broadly
rounded in front, and extends about three-fourths of the total length across the valve.

Length 7 mm., height 4f, diameter of valve If.

Habitat. — Station 185b, east of Cape York, North Australia, in 155 fathoms; coral
sand.

88 THE VOYAGE OF H.M.S. CHALLENGER.

Semele (Abra) longicallus (Scacclii). -"^

TeJlina longicallus, Scacclii, Notizie Concli. foss. di Gravina, itc, p. 16, \>]. i. fig. 7.
Erycina longicalUs, Philippi, Euum. Mol. Sicil., vol. ii. p. 9, pi. xiii. fig. 7.
Alira loiifficall is, Sars, Moll. Eeg. Arct. Norv., p. 74, pi. vi. figs. 3a-c, pi. xx. fig. 4.
Syntlosmija longicalUs, Dall, Bull. Mus. Comp. Zool., Harvard College, vol. ix.. No. 2, p. 133.
Scrohicularia loiigicallns, Jetfrej'S, Proo. Zool. Soo. Lond., 1881, p. 926.

Habitat. — Station 75, off the Azores, in 450 fathoms ; volcanic mud.

For the distribution of this species, which occurs in many phices, and at vastly
different depths in the Atlantic, and also in a fossil state in Italy and Norway, reference
should be made to the paper by Dr. Gwyn Jeffreys quoted above.

Semele [Abra) j^rofunclorum, n. sp. (PI. Y. figs. 5-56).

Testa leviter iufequilateralis, transversim ovato, postice hians valdeque acuminata,
subcompressa, tenuis, subdiaphana, alba, polita, conceutrice exiliter striata, antice
anguste lunulata, postice area lineare instructa. Umbones ^ arvi, acuti, paululum pone
medium siti. Margo dorsalis posticus obliquissimus, subrectus, anticus prope umbones
leviter concavus, deinde vix excurvatus. Dentes cardinales duo in utraque valva, valde
intequales. Sulci laterales in dextra angusti, profundi, ab apice subremoti. Fossa pro
ligamento angusta, elongata. Impressiones musculares insequales, antica elongata, postica
rotunde pyriformis. Sinus pallii latus, profundissimus. Fascies valvarum interna
plerumque polita, seel in medio, umbonesque versus minutissime subgranulata.

This sjjecies is longer than high, broadly rounded in front and ratlier acuminate at
the hinder end. The shell is inequilateral, the anterior portion being rather the longer,
very thin, transparent, ami moderately flat and slightly gaping posteriorly. The surface
is smooth and glossy, and sculptured with fine concentric strife or lines of growth, and in
addition faint indications of very unimportant radiating sculpture are traceable. The
hinder dorsal slope descends very obliquely, and is almost rectilinear. The anterior
margin is much more horizontal and slightly arcuate, except close to the umliones, where
a faint conca\"ity is met with. The lunule is elongate, narrow, and defaced by a slight
but distinct ridge on each side. The area is also narrow and defined by a sharpish ridge
on each valve extending just beyond the lateral teeth. In addition to this there is a
second but less acute angle on each A'alve, forming, as it were, a second larger area
reaching to the posterior extremity of the shell. The beaks are small, acute, and
a little elevated. The cardinal teeth are two in number in each valve. In
the right the posterior is twice as large as the front one, whilst in the left it is
smaller, thin, lamellar, and borders the cartilage-pit. The lateral dental grooves in the
dextral valve are narrow, deep, and moderately distant from the umbo, which they
do not reach on either side. The internal ligament-pit is long and narrow, and parallel

REPORT ON THE LAMELLIBRANCHIATA. 89

with the hinder slope. The interior of the valves is somewhat glossy towards the outer
margins, whilst in the centre and subumhonal region it is minutely suljgranular. It is
also marked with a faint radiating substriation. The anterior nmscular scar is very
elongate, pyriform, and not nearly so broad as the posterior. The siphonal inflection is
broad, and terminates in a sharply rounded extremity far beyond the middle of the valves.
From this extremity a shallow groove extends towards the beaks, and a similar impressed
ray (although insignificant) is generally ol:)servable radiating from llic uuilio to the inner
margin of the posterior adductor scar.

Length 18 mm., height 12, diameter Sf. A smaller specimen is 12| long, 8^ high,
and 3^ in diameter.

Habitat. — Station 85, near the Canaiy Islands; depth, 1125 fathoms. Station 73,
west of the Azores; depth, 1000 fatlioms. Station 98, west of Sierra Leone, in 1750
fathoms. Station 244, Mid North Pacific, at a depth of 2900 fathoms.

Two specimens from the last locality I fail to distinguish from those from the
Atlantic. They may be a little narrower and not Cjuite so acute posteriorly, but with the
exception of these trifling and possibly individual peculiarities I can discover no essential
specific differences. Ahra longicallus (Scacchi) closely resembles this species, but is a
little narrower, not quite so acute at the posterior end, and has a shallower pallial sinus.

Semele (Theora) iridescens (Hinds) (PI. V. figs. 6-6h).

Necera iridescens, Hinds, Proc. Zool. Soc. Lond., 1843, p. 78.
Theora iridescens, H. and A. Adams, Gen. Eec. Moll., vol. ii. p. 370.
Theora iridescens, A. Adams, Ann. and Mag. Nat. Hist., 186-4, vol. xiii. p. 209.
Theora iridescens, Tryon, Amer. Journ. Concli., vol. iv., Appendix, p. 118.

Testa tenuis, subhyalina, vitreo-alba, valde nitida, inasquilateralis, 8ec[uivalvis,
utrinque anguste hians, antice lata, rotundata, postice cuneata, paulo veutricosa,
incrementi lineis striata. Margo dorsi anticus primo vix arcuatus, dein oblique curvatus,
posticus recte declivis. Ventris margo late arcuatus, postice leviter sinuatus. Umbones
mediocriter magni, supra cardinem paulo prominentes. Denies cardinales duo ante
fossam ligamenti in valva dextra coUocati, unicus in valva sinistra. Denies laterales
utrinque tenues, prominentes. Fossa cartilaginis obliqua, intus recedens. Sinus paUii
magnus, profundissimus. Pagina interna radiatim et confertim striata.

Length 17^ mm., height 11, diameter 8.

Habitat. — Amboina, in 15 to 20 fathoms (Challenger) ; Island of Luzon, Philippines
(Hinds) ; Yobuka, Japan (A. Adams).

The above description is drawn up from the t}-pe specimens in the British Museum, as
the single valve obtained by the Challenger is but immature. From this it will be seen
that the details of the hinge do not correspond with the description given by Messrs.

(zool. CHALL. EXP. — PART XXXV. — 1885.) Mm 12

90 THE VOYAGE OF H.M.S. CHALLENGER.

Adams, wlio iiiakL' no meutiou of lateral teeth. These are very thin in this species, and
rather close to the beaks, especially the front one. In the right valve they are separated
from the dorsal line liy a narrow groove which receives the elevated marginal teeth of the
opposite valve. Indeed I fail to perceive hardly any difi'erence between the genus Thcora
and Abra, except that the cartilage-pit may be rather larger in most species of the former
than in any forms of Ahra with which I am acquainted. The form and texture of the
shell are similar in both groups, and the pallial sinus is likewise large and deep. In the
Annals and Magazine of Natural History for 1864, vol. xiii. p. 208, Mr. A. Adams
again characterises Theora, stating that there are no primary teeth, and in describing
Theora (NecBva) fragilis (Proc. Zool. Soc. Lond., 1855, p. 226) he observes that "there
are no lateral teeth." Such assertions as these show how very superficial his examination
(jf the sjjecies he cites must have been, for all have true cardinals as well as lateral teeth.
The subgenus Eridojolemu, which he founds on the Theora lumbrica of Gould, is not in
my opinion worthy of retentioii. It differs only from other forms of Theora in possess-
ing a radiating ridge or rib within tlie valves extending from the beaks obliquely towards
the anterior end.

This genus (Theora) was formerly placed by the brothers Adams near NeoBva, but
afterwards was removed by A. Adams to the Telliuidae, a location which is probably
correct. He says " the deep sinus in the pallial line, together with the form of the
valves and the pellucid vitreous texture of the shell, clearly show that this genus belongs
to the Scrobiculariate division of the Tellinidse, and not very far from the Abra of
Leach or Sy)idos)iii/a of Reeluz."

Family T E L l i n i n m.

Subfamily Psamjiobiin.^.
Psammobia, Lamarck.

Ps^ammobia ' costulata, Turton.

Psammohia cosfulafa, Turton, Conch. Ins. Brit. Dithyra, p. 87, pi. vi. fig. 8.

Psanimohia costulata, Brown, 111. Conch. Gt. Brit., pi. xxxi.K. fig. 34.

Psammohia costulata, Philippi, Abbild., vol. i. p. 98, pi. i. figs. 3, 4.

Psammohia costulata, Keeve, Conch. Icon., vol. s. fig. 38.

Psammohia costulata, Forbes and Hanley, Brit, lloll., vol. i. p. 279, pi. xix. fig. 5.

Psammohia costulata, Jeffreys, Brit. Conch., vol. ii. p. 394, vol. v. p. 187, pi. xlii. fig. 2.

Psammohia discors, Philippi, Enum. Moll. Sicil., vol. i. p. 23, pi. iii. fig. 8.

Habitat. — Tenerife, Canary Islands, at a depth of 70 fathoms.

This species has already been recorded from these islands. It has a wide range,

' The generic name Gari of Schumacher was published iu 1817, a year previous to Lamarck's Psammobia ; the
latter, however, being generally adopted, and more in accordance with the accepted notions of zoological nomenclature,
should, I think, be ineferred.

REPORT ON THE LAMELLIBRANCHIATA. 91

having been met with in tlie Mediterranenn, at Madeira, and off the Norwegian and
Britisli coasts.

Psammohia pidcherrima, Deshayes.

Psammohia pulchern'ma, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 325.
Pganmiohia pulchcrrinia, Reeve, Conch. leoii., vol. ,k. iig. 46.

Habitat. — Station 172, off Nukalofa, Tongatalju, in 18 fathoms; coral mud.

The habitat of this species lias hitherto Ijeeu unknown. The type shell tigured liy
Reeve is only half-grown, and on this account has been described as " thin." The .single
specimen obtained by the Challenger is probably adult, and at this age is rather a thick
shell in comparison with many other species of this genus. It is 31 mm. long. 15 high,
and 8^- in diameter.

It is of a yellowish tinge ornamented with several slightly arcuate .sanguineous rays,
and tinted at the hinder extremity with pale rose. The interior is painted somewhat
like the outside, except that the rays are rather more purplish and clouded. The valves
are very slightly inequilateral, the anterior side being the shorter, but not so dispropor-
tioned as represented by the figure in the Conchologia Iconica. They are transversely
elongate, only half as high as long, moderately convex, having the anterior two-thirds of
their surface coarsely obliquely sulcate and ridged, the ridges being broader and the
intervening grooves narrower than posteriorly, where they terminate abruptly at the
first of the oblique radiating costse which adorn the hinder pqrtion of the surface. These
are ten in number, gradually thicken as the shell enlarges, are separated by deep furrows,
and in the early stages of growth or towards the umbones are more or less nodulose.
The single tooth of tlie left valve and the posterior in the right are somewhat cleft at
the tip, the front one in the latter valve being broad and oblique. The pallinl sinus is
large, deep, rounded at the end, and extends beyond the centre.

Psammohia castrensis (Spengier).

Solen castretisis, Spengier, Chemnitz, Conch. Cab., vol. xi. p. "201, pi. cxcviii. figs. 193.5, 1D36.
Solen castrensis. Wood, Index Test, pi. iii. fig. 25.
Psammohia castrensis, Hanley, Cat. Biv. Shells, p. 59.
Psammohia castrensis, Reeve, Conch. Icon., vol. x. fig. 32.
Psammohia oriens, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 318.
Psammohia oriens. Reeve, Conch. Icon., vol. x. fig. 1.
' Psammohia oriens, Dunker, Index Moll. Mar. Japon., p. 186.

Habitat. — Station 172, off Nukalofa, Tongatabu, in 18 fathoms ; coral mud.

A single specimen from this locality, dredged in a dead condition, differs from the
tjrpical form in having the po.sterior end of the shell more strongly sculptured than usual.

92 THE VOYAGE OF H.M.S. CHALLENGER.

The elevated lamellse extend about half way across the valves, and are well developed,
whilst in ordinary examples they do not pass beyond the hinder umbonal ridge. The
teeth, pallial sinus, and musciilar imju-essions are similar, and the painting, which is"of m
bright pink-scarlet colour, has a like disposition.

Psammohia oriens I consider the adult form of this species, and at this age (being
much thicker) the external campdike markings are concealed within Ijy a shelly deposit.

The specimen figured by Chemnitz is a young shell, and said to have come from the
coast of Guinea. Should this be true, my association of Psammohia oriens with this
species would probably be incorrect. However, I believe this identification to be accurate,
for the shell figured by Reeve from the Philippine Islands and another in the British
Museum from Hainan correspond very closely with the description and figure of Chemnitz.
Psammohia oriens was described from Japanese specimens, and in the Cumingian collec-
tion there are others from Torres Strait.

Psammohia sp.

Hahitat. — Off Amboina, in 15 to 20 fathoms.

A single, apparently young, valve is all that was dredged. It very closely resembles
Psammohia weinkauffi, Crosse, from the Algerian coast, judging from the description and
figure in the Journal de Conchyliologie, 1864, vol. xii. p. 17, pi. ii. fig. 4, and, had I not
known that it came from so distant a locality as Amboina, 1 should not have hesitated
to have identified it with that species. The oldique strife may possibly prove on
comparison a trifle coarser, and probably other characters will be observable which ' will
separate the two forms.

Psammohia lineolata, Gray.

Psammohia lineolata, Gray, Dieflfenbach's New Zealand, vol. ii. p. 2b'i.

Psammohia lineolata, Hanley, Cat. Biv. Shells, p. 59, Appendix, p. 346, pi. xiv. fig. 1.

Psammohia lineolata, Eeeve, Conch. Icon., vol. x. fig. 58.

Psammohia lineolata, Hutton, Manual N. Zeal. Moll., p. 142.

Psammohia lineolata, Smith, Voy. "Erebus" and "Terror," pi. ii. fig. 11.

Psammohia convexa, Eeeve, Conch. Icon., vol. x. fig. 59, a, h.

Hahitat. — Station 167a, Queen Charlotte Sound, near Long Island, New Zealand, in
10 fathoms ; mud.

This species, according to Hutton, is common, and ranges from Auckland to Dunedin
and the Chatham Islands. It is elongate, suboval, rather narrower anteriorly than
behind, almost equilateral, glossy, sculptured with fine concentric lines of growth, pinkish,
sometimes reddish-pink, varied with paler and darker concentric zones, and very minute
anastomosing subradiate, more or less pellucid, lines. At times specimens are met with

REPORT ON THE LAMELLIBRANCHIATA. 93

wliicli arc faintly rayed. The valves are comj^ressed, especially in young shells, and
gape at both cuds. The anterior dorsal margin is moderately oblique, very slightly
convex, the posterior being rather more horizontal and generally a little concave. The
anterior side, which is a trifle shorter than the posterior, is rounded at the extremity, tin-
hinder side terminating more sharply at a point rather low down, where a feeble ridge
radiating from the umboncs terminates. The ventral outline is widely arcuate, and
ascends a little hioher in front than behiiid. The two teeth of the right valve are both
bifid, erect, and divergent from one another. The left valve also has two teeth, one
erect, cleft at the top, similar to those in the right valve, the other being less conspicuous,
oblique, thin, lamellar, almost obsolete in some specimens, and situated l)eliind the mort-
prominent tooth which fiills just lieneath the uml)o. The muscular scars are large, about
equal in size, the anterior being usually of a more elongate form. A third smaller deepish
scar is situated beneath the hinge-line, a little in advance of the teeth. The 25allial sinus
is in every case deep, although not always equally so, and is irregular at times in form.

Psammohia convexa, Eeeve, is undoubtedly the same species as the present. The
two specimens figured in the Conchologia Iconica are rather thick old shells, and a trifle
more convex than usual, Init answer the above description in every other detail.

Tlie Tasmanian Psammohia zonalis, Lamarck, is very closely allied, and perhaps
scarcely w^orthy specific separation, but may be distinguished thus. It is somewhat
smaller, not usually quite so glossy, more strongly striate, especially at the posterior end
and near the ventral edges, and generally of a less pinkish tinge. With Psammohia
zonalis I have no hesitation in uniting Psammohia tellinceformis, Deshayes, Psammohia
puella, Deshayes, and Psammohia striata, Deshayes, the last being, I believe, a manuscript
name attached to specimens in the British Museum, from between West Hill and Cape
Upstart, Australia, collected by J. B. Jukes, Esq.

Psammohia pallida, Deshayes.

Psammohia 2'Mi<ln, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 323.
Psammohia nialaccana. Reeve, Conch. Icon., vol. x. tig. 42.
Psammohia stiff u-sa, Reeve, loc. cif., fig. 54.

Hahitat. — Station 188, west of Cape York, North Australia, in 28 fathoms; green
mud (Challenger) ; Red Sea (type in Brit. Mus.) ; Malacca (Reeve for Psammohia
malaccana and Psammohia siifusa) ; Lane Cove River, New South Wales (Brit. Mus.).

There is no difference whatever excepting that of colour between Psammohia pallida
and Psammohia malaccana, the former being of a pale lilau tint, faintly rayed with a
darker hue, and the latter being purely white. Psammohia sujf'usa I regard merely as the
young state of a more highly coloured variety. The sculpture of all three is precisely
similar, the oblique striae terminating abruptly in an oblique line easily recognisable to

94 THE VOYAGE OF H.M.S. CHALLENGER.

the naked eye, as the portion of the surface behind the line is far less glossy than the
remaiuder. The dentition of all is the same, consisting of two cardinal teeth in each
valve, all bifid, with the exception of the posterior in the left, which is smaller than the
others and oblique. In addition to these, there is in each valve a more or less distinct
lateral tooth rather remote from the cardinals. The type of this species is in the British
Museum, with the locality " Eed Sea " attached to it, but I am unable to discover upon
what authority it is so labelled. No mention is made of Psammohia pallida by Reeve,
whose monograph, with two exceptions, is based upon the specimens contained in Mr.
Cuming's collection. The fact of this shell having lateral teeth should remove it from
this genus. However, the " tout ensemble " is so Psammobia-like (and I find other
forms intermediate with respect to this character) that I tliink it may properly l)e ullowed
to remain with this group.

Psammohia intermedia, Deshayes.

Psammohia wtermedia, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 319.

Psammohia intermedia, Eeeve, Couch. Icou., veil. x. fig. 25.

Gari intennedia, Tryon, Cat. TellinidiB in Amer. .Journ. Conch., vol. iv., Apjieiidi-x, ji. 74.

Habitat. — St. Vincent, Cape de Verde Islands, in 7 to 20 fathoms (Challenger) ;
coast of Portugal (Deshayes).

The Challenger specimens of this species are only about half the length of the shell
figured by Reeve, and more brightly variegated witli a rosy purple tint, the interior
exhibiting the markings more vividlv than the exterior.

Psammohia zonalis (Lamarck).

Psammotcea zonalis, Lamarck, Anim. Sans Vert., ed. 2, vol. vi. p. 182.

Psammotcea zonalis, Delessert, Eecueil, pi. v. fig. 9, a-c

Psammotcea zonalis, Hanley, Cat. Eec. Biv. Shells, p. 60, and Appendix, p. .346, pi. xi. fi<;. 50.

Psammohia zonalis, Reeve, Conch. Icon., vol. x. fig. 29.

Psammohia tellinmformis (Deshayes) Reeve, loc. cit., fig. 31.

Psammohia puella, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 320.

Psammohia puella, Reeve, Conch. Icon., fig. 2.

Psuinmohia striata, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 321.

Psammohia compta, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 321.

Psammohia compta,, Reeve, loc. cit., fig. 24.

Psammohia radiata, Dunker, in Philippics Abbildungen, vol. i. p. 194, pi. ii. fig. 5.

Habitat. — Port Jackson, Sydney, in 4 to 18 fathoms.

This species has also been found at Amboina, Java, Philippine Islands, and '^asmauia.
It varies somewhat in painting, some forms being more rayed than others. In all, how-
ever, the apices of the umbones are pale, and the interior of the valves more or less lilac.

PvEPORT ON THE LAMELLIBRANCHIATA. 96'

Fsammobia anomala, Deshayes.

Pi-ammohia anumalu, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 320.
Psammohia anonlala, Keeve, Conch. Icon., vol. x. fig. 5.
Var. = Pxammohia fenids, Reeve {rwn Deshayes), loc. cit, fig. 37a.

Habitat. — Cape York, North Australin, iii 3 to 12 fathoms (Challenger) ; Philippine
Islands, Zebu (Deshayes) ; Brisbane Water, east coast of New Holland (Reeve) ; Torre.s
Strait (Coll. Cuming).

The single specimen from Cape York is coloured precisely like the tyjiical shell
figured by Reeve, and that from Torres Strait in the Cumingian collection is similarly
painted. In this form the oblique posterior ridge is more strongly marked than in the
variety figured by Reeve as Psammohia tenuis. The latter species may be known from
Fsammobia anomala, by the total absence of lateral teeth on the posterior side, the
presence of which in this species approximates it to Psammohia pallida. It is,
however, narrower and more finely sculptured than that form.

Psammohia modcsta, Deshayes.

Psammohia modesta, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 319.
Psamtnoh'a modesta, Eeeve, Conch. Icon., vol. x. fig. 3.
Psammohia menkeaua. Reeve, loc. cit., fig. 43.

Psammohia angusta, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 320.
Psarmnohin anrjusta, Reeve, Conch. Icon., fig. 44 (bad).

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

This species also ranges further north to Moreton Bay, if that locality, the first
assigned to it, can be relied upon.

The typical form externally is of a bluish-white colour, ornamented with a few purple-
red rays, chiefly developed near the ventral outline, and more or less pinkish-violet
within. A single valve obtained by the Challenger and a specimen in the British
Museum collected during the voyage of the " Rattlesnake" are of an orange-red tint
within and without, being paler towards the margins and at the apex of the umbones.
Other specimens, also from Port Jackson, I have seen which are totally white. The
concentric striation of this species is fine, being most conspicuous at the anterior end.

Tellina menheana, Reeve, is identical with this species, although, judging from the
two figures in the Conchologia Iconica, the one appears to be a much more slender
shell than the other. This arises from two causes. In the first place the shell
depicted in fig. 3 is not so broad in reality as the drawing, and that represented in
fig. 43 has the ventral margin of the valves broken away somewhat, so that the form
appears more elongate than it would if the specimen were perfect. I also fail to discover
any character in Tellina angusta which will separate it from this species. The locality

06 THE VOYAGE OF II. M.S. CHALLENOER.

assigned to it, uamel)" Senegal, I reganl merely as one of tlie numerous errors of this
description occurring in the collection of Mr. Cuming.

Bubfamil}^ Tkllinin^.

Tellina, Linne.

Tellina (Macoma) consociata, n. sp. (PI. IV. figs. 4-4?^).

Testa paulo insequilateralis, ovato-trigonalis, alba, epidermide caduca lutescenti induta,
postice parum hians, dextrorsum subflexuosa, valva dextra quam sinistra aliquanto
planiore, parte antica subelongata, ad finem medioeiiter acute rotundata, postica multo
breviore, cuneiformi, ad extremitatem oblique truucata ; valvse tenues, subnitentes, incre-
menti lineis tenuibus striatfe. Margo dorsi anticus declivis, subrectilinearis, elougatus,
posticus magis obliquus, rectus, brevior, margo ventralis late arcuatus, antice regulariter
adscendens, postice vix flexuosus. Dentes cardinales valvpe dexbraj duo, posteriori bifido,
in sinistra unicus pariter bifidus. Pallii sinus maguus, spatium subquadrangulare in-
cludens. Pagina interna alba, radiatim suljstriata.

This shell is moderately thin, somewhat inequilateral and inequi\'alve, the right being
slightly less convex than the left. It is longer than high, triangularh' ovate, sharply
rounded in front, wedge-shaped, and shortly truncated behind, very slightly gaping at the
posterior end, which is bent a little to the right. It is of a pure white colour, more or
lass concealed by a clay-coloured caducous epidermis which is a little reflexed within the
margin of the valves. The sculpture consists of fine concentric lines of growth and traces
of radiating substrise. The umbones are small, acute, and located somewhat behind the
central point. The front dorsal margin is long, onl}- slightly oblique, almost straight or
very feebly excurved, the posterior lieing rather shorter, rectilinear, and very sloping.
The ventral outline is gently curved, a little more ascendant in front than l)eliind, where
there is only the faintest indication of a sinus. Both valves are shallowly grooved down
the posterior side, the left rather more distinctly than the right. The hinge consists
of two cardinal teeth in the right valve and one in the left, the posterior in the former
and that in the latter being cleft at the summit. The interior of the valves is white, and
marked with faint radiating substrise. The pallial sinus is large, and extends considerably
beyond the centre, the circumscribing line forming a somewhat quadrangular figure.

Length 22 mm., height 151, diameter 8.

Habitat. — South of Amboina, at a depth of 15 to 25 fathoms.

This species closely resembles the shell figured by Hanley (Thesaurus, fig. 13) as the
Tellina umbonella of Lamarck. The locality, " Port Lincoln," which he assigns to it is
probably taken from a specimen in the British Museum said to have come from that place.
In the Proceedings of the Zoological Society, 1871, p. 727, I quoted this species from

REPORT ON THE LAMELLIBRANCHIATA. 97

Wliydali on the west coast of Africa. I am inclined to consider the former " habitat "
incorrect, for there is little likelihood of West Africa and South Australia producing the
same species. There is no doubt regarding the correctness of the locality Whydah, for
the specimens of this species referred to were dredged by Captain Knocker together with
a number of others, all of which are West African types.

The present species has a more triangular appearance, is a little narrower, rather more
acuminate at both ends, and lacks the broad reddish ray near the umbones. The
posterior dorsal slope is longer and a trifle more oblique, so that the apical angle is also
somewhat more acute.

Tellina {Macoma) uruguayensis, n. sp. (PI. IV. figs. 5-56).

Testa tenuis, insequilateralis, transversim elongata, utrinque hians, postice angustata,
subrostrata, dextrorsum conspicue flexa, antice rotundata, parum ineequivalvis, alba,
epidermide lutescenti prope marginem induta, striis incrementi tenuibus insculpta.
Margo dorsi anticus elongatus, vix descendens, leviter arcuatus, posticus brevior, prope
umbones paulo concavus dein, rectus, valde declivis. Ventris margo lente curvatus,
postice in valva sinistra levi.ssime sinuosus. Dentes cardinales valvse dextraj duo, parvi,
in valva sinistra unicus. Pallii sinus profundus, ad finem rotundatus. Pagina interna
alba, aliquanto iridescens, radiatim substriata.

This species is very much longer than high, thin, white, finely striated by lines of
growth, and more or less covered near the ventral margin Ijy a dirty yellowish epidermis.
It is considerably inequilateral, the anterior side laeing the larger, rounded at the extre-
mity, and scarcely narrowing ; the hinder portion, on the contrary, is considerably
attenuated or subrostrate, and narrowly truncated at the extremity. The valves are a
little unequal, the left being rather more convex than the other. Both are turned
conspicuously to the right at the hinder end, and gape somewhat on both sides. The
front dorsal outline is faintly arcuate and only a very little oblique. The posterior,
which is shorter, being much more sloping, at first, close to the beaks a little concave and
then almost rectilinear. The lower margin is but very slightly arched near the middle,
rises in a gentle curve anteriorly, and behind exhibits in the right valve a very faint
trace of an incurvation or sinus. The ligament is sordid yellow, short and prominent.
The hinge is composed of two small prominent teeth in the right valve and a single one
in the left. The inner surface of the valves is white, somewhat iridescent and radiately
substriated. The anterior muscular scar is elongate and irregular in outline, the posterior
is shorter and broader. The siphonal inflection is ver)^ deep, narrow, rounded at the
extremity, the line which encloses it returning about half way across the valves before
joining the other part of the pallial line, parallel with the ventral margin.

Length 22 mm., height 12^, diameter 6.

Habitat. — Station 321, off" Monte Video, Uruguay, in 13 fathoms; mud.

(ZOOL. CHALL. EXP. — PART XXXV. 188.").) Mill 1.3

98 THE VOYAGE OF H.M.S. CHALLENGER.

This species ranges further north as far as the West Indies. Specimens from the
Island of St. Thomas in tlie British Museum are perhaps a trifle longer in proportion to
their height than the examples from Monte Video. The largest of the Caribbean shells is
29 mm. long, IG high, and 8 in diameter.

Tellina [Macoma) arafiirensis, n. sp. (PI. IV. figs. 6-6?>).

Testa transversim oblonga, antice rotundata, postice angustata, truncata, modice
convexa, valde insequilateralis, alba, paulo iridescens, epidermide tenui flavo-grisea partim
induta, lineis incrementi concentricis, striisque tenuissimis radiantibus insculpta. Valvse
jjostice prope marginem dorsalem sulco inconspicuo decurrente signatse, aliquantoque
hiantffi. Margo dorsi anticus elongatus, parum obliquus, leviter arcuatus, posticus valde
declivis, rectilinearis. Ventris margo antice arcuatus, latus posticum versus inconspicue
subsinuatus vel incurvatus. Area lanceolata, profunda, marginibus subacutis inclusa.
Dentes cardinales parvi, in valva dextra duo, posticus valde fissus, in sinistra unicus,
erectus. Pallii sinus magnus, subquadratus, fere ut in Tellina truncata, Jonas.

Length 47 mm., height 30, diameter 14.

jfZct5?'to/.— Station 190, Arafura Sea, in 49 fathoms; green mud.

This species is somewhat intermediate in its characters between Tellina galatcea,
Lamarck, and Tellina truncata, Jonas. It is not quite so elongate as the former, but
rather more prolonged than the latter. It differs from Tellina galatcea also in sculpture,
being less coarsely radiately striated, not granular, lacking the peculiarly sculptured rays,
and it is also faintly iridescent. The posterior side of lellina arafurensis ends in a
narrower truncation, and the dorsal slojie is rather more abruptly descending, yet not so
suddenly oblique as in Tellina truncata. The latter is decidedly higher, and the hinder
dorsal margin or ligamental slope being more abruptly oblique, the apical or umbonal
angle is more acute than in the present species. Tellina guhernaculioji, Hanley, said to
liave been found on the west coast of Central America, is also very closely allied to the
species under consideration. It has a broader truncated end posteriorly, and a shorter
ligamental margin than Tellina arafurensis.

Tellina murrayi, n. sp. (PL III. figs. 8-86).

Testa transversa, elongata, tenuis, paulo ina3C[uilateralis, albida, versus umbones
pallide flavescens, semipellucida, liris tenuibus concentricis aliisc^ue confertioribus
radiantibus minus conspicuis concinne ornata. Margo dorsi utrinque leviter sequaliterque
declivis, antice vix convexus, postice primo paulo concuvus. Margo ventralis late cur-
vatus, latum posticum subrostratum versus subsinuatus, antice adscendens, rotundatim in

REPORT ON THE LAMELLIBRANCHTATA. 99

(lorsalcm ambiens. Umbones parvi, acuti, subprominentcs. Cardo normalis, dente postico
valvsc (lextrse, antico in sinistra triangulari bifido, lateralibus fere ijjquidistantibus.

This shell is transversely elongated, sharply rounded in front, narrowed and some-
what rostrate at the opposite end. It is slightly inequilateral, the anterior side being a
little the longer. It is thin, semipellucid, whitish or tinted with pale yellow at the
upper part, and ornamented with fine concentric lirse which are more numerous upon the
anterior half of the valves than behind. Besides these there are others more closely
packed and scarcely visible to the naked eye which radiate from the small acute
prominent umbones and produce upon the concentric ones a somewhat crenulate appear-
ance. The dorsal margin is about ecj^ually sloping on both sides, straight or the slightest
convex anteriorly, and feebly concave at first Ijehind the umbones. The lower outline
is broadly arcuate at the middle and in front, but slightly incurved posteriorly. The
dentition of the hinge is the same as in the typical section of the genus, and the paUial
sinus is deep and rounded at the end.

Length 8 mm., height 4 J, diameter 2.

Habitat. — Station 185b, off" Cape York, North Australia, in 155 fathoms; coral
sand.

The specimens here described are possibly young shells, but the peculiarity of the
sculpture will readily distinguish the species.

Tellina compacta, n. sp. (PL III. figs. 9-9e).

Testa elongata, subdonaciformis, valde inaequilateralis, antice rotundata, postice
angustata, subcuueiformis, mediocriter convexa, alba, interdum dilutissime rosea, zonis
angustis paucis peUucidis ornata, incrementi lineis fortiter striata. Margo dorsi anticus
perelongatus, parum declivis, subrectihnearis, posticus valde obliquus, rectus, brevis.
Margo ventris leviter arcuatus, anterius rotundatim, posterius parum adsceudens.
Umljones parvi, acuti, circiter in \ longitudinis collocati. Dentes cardinales duo
lateralisque unicus in utracpie valva ; ligamentum breve, flavo-fuscum, prominens. Pagina
interna nitens, paulo iridescens, pallii sinu magno profundo notata.

The form of this species recalls that of certain varieties of the genus Donax. It is
not quite twice as long as high, rounded and only slightly narrowing antei-iorly, much
shorter behind, narrowed and somewhat wedge-shaped. It is very inequilateral, the
anterior side constituting by far the larger portion of the shell. It is moderately strong
and thick, a little convex, slightly gaping at both ends, whitish, or witli a l)]nsh of pink,
varied at intervals with narrow bluish somewhat pellucid zones, and sculptured with fine
concentric lines of growth, which, howcA'er, are rather coarser near the ventral edge.
The front dorsal margin is almost twice as long as the posterior, almost horizontal and

1(10 THE VOYAGE OF H.M.S. CHALLENGER.

straight. The hinder slope is very oblique and also straightish. The ventral outline is
but slightly excurved, not sinuated posteriorly, regularly up-curved in front, forming
with the dorsal margin an obtuse rounded extremity. At the opposite end it is less
ascending and forms a blunt angle at its junction with the lateral outline. The hinge is
composed of two cardinal teeth and a single anterior lateral in each valve. Of the
former the posterior in the right valve, and anterior in the left, are triangular, Ijifid, and
much larger than the others, and the lateral tooth of the right valve is more conspicuous
than that of the left, which consists merely of a slight prominence of the dorsal edge.
The ligament is shortish, yellow-brown, and prominent. The inner surface of the valves
is glossy, somewhat iridescent, and exhibits a deep large pallial sinus extending almost
to the anterior scar.

Length 19^ mm., height 11, diameter 5j.

Habitat. — Station 187, off Cape York, North Australia, in 6 fathoms ; coral mud.

This species is considerably like the European Tcllina donacina, Liund, as regards
form, Ixit rather more tapering at the anterior end, somewhat shorter and scarcely so
acuminate posteriorly, and the sculpture is a little coarser.

Tellina {Tellinella) verrucosa, Hanley.

Tellina verrucosa, Hanley, in Sowerby's Thesaurus, vol. i. p. 225, pi. Iviii. fig. 77.

Tellina verrucosa, Sowerby, Concli. Icon., vol. xvii. fig. 96.

Tellina (Tellinella) verrucosa, Eomer, Conch. -Cab., ed. 2, p. 23, pi. ix. figs. 1-3.

Habitat. — Station 172, off Nukalofa, Tongatabu, in 18 fathoms (Challenger) ; Bay of
Manila, Phili^jpine Islands (Cuming).

This species is narrower and more rostrate than Tellina asperrima, Hanley, Tellina
pulcherrima, Sowerby, Tellina semiaspera, Deshayes, and Tellina squamulosa, which have
more or less similar style of sculpture.

Tellina (Tellinella) charlotta', n. sp. (PI. IV. figs. l-l6).

Testa tenuis, albida, umbones versus lutescens, valde inferpiilaterahs, elongata, antice
rotundata, postice acuminata, ad extremitatem breviter truncata, concentrice tenuiter
lirata, liris postice hie iUic anguste lamellatis. Margo dorsi anticus parum oliliquus, \'ix
curvatus, posticus brevior, valde dechvis, rectilinearis. Margo ventris leviter arcuatus,
postice vix sinuatus. Dentes cardinales valvse dextras duo divergentes, unicus in valva
sinistra subbifidus. Laterales tenues fere sequidistantes. Sinus pallii profundissimus
fere ad cicatricem anteriorem extensus.

This species is entirely white with the exception of a very faint tinge of yellow towards
the beaks. It is thin, compressed, very inequilateral, the anterior side 1)eing considerably
longer than the posterior. It is transversely elongated, sharply rounded in front, and

KEPORT ON THE LAMELLIBRANCHIATA. 101

shortly wetlge-shapccl liehind, terminating in a short truncation. The surfiice is not highly
glossy, but has a silky, faintly iridescent, appearance. The sculpture consists of numerous
concentric thread-like lirse which become gradually thicker as the shell increases. They
do not all extend quite to the hinder margin, l>ut stop short at a slight fold radiating
from the beaks to the lower hindmost extremity. Some of them, however, do reach
the margin, and these are elevated into short lamellse, those on the right valve being a
little flexuous. The front dorsal slope is the slightest excui-ved, and descends only a little.
The posterior is shorter, very straight and very oblique. The lower outline is slightly
arcuate, and very feebly sinuated posteriorly. The interior is glossy, radiately substriated,
and exhibits a pale yellow stain towards the umbones. There are two cardinal teeth in
the right valve and one in the left, that in the latter, and the posterior in the former,
being somewhat cleft at the top. The lateral teeth are slender, elongate, the anterior
being rather nearer the beaks than the posterior. The pallial sinus is large and deep,
extending almost to the front muscular impression.

Length 14 mm., height 8-|, diameter 3-J-.

Habitat. — Station 167a, Queen Charlotte Sound, Cook Strait, New Zealand, in 10
fathoms ; mud.

Tellina {Tellinella) huttoni, u. sp. (PL IV. figs. 2-2h).

Testa tenuis, compressa, valde in8ec|uilateralis, oblonga, antice rotundata, postice
acuminata, nitida, concenti'ice tenuiter striata, dilute rosacea. Margo dorsi anticus
elongatus, vix declivis, pene rectilinearis, posticus brevior, obliquissimus, rectiusculus.
Margo ventris parum arcuatus, antice curvatim ascendens, postice baud sinuatus.
Umbones acuti, albi, in J longitudinis locati. Dentes cardinales duo in utraque valva,
postico valvse dextrse et antico sinistrse crassioribus, triangularibus. Dentes laterales
in valva dextra distincti, anteriori cardinalibus approximato, posteriori remote. Sinus
pallii profundissimus, fere ad cicatricem anteriorem productus.

This species is very closely related to Tellina glahrella, Deshayes, also from New
Zealand, and indeed it is with some degree of hesitation that I venture to separate it. It
is a trifle more inequilateral, of a pinkish colour, has the anterior dorsal line longer and
less sloping, the beaks rather less prominent, and the anterior lateral tooth rather
more approximated to the cardinals than is the case in Tellina glahrella.

Length 10 mm., height 5f, diameter 2.

Hahitat.—^t&tion 167a, Queen Charlotte Sound, Cook Strait, New Zealand, in 10
fathoms ; mud.

Only a single specimen of this species was brought home, which possibly is not of the
full size it sometimes attains. It is a small pinkish shell, having the right valve a trifle
flatter than the left. It is thin, wedge-shaped behind, broad and rounded in front.

102 THE VOYAGE OF H.M.S. CHALLENGER.

Tellina (Angulus) valtonis, Hauley.

Tellina vnUonis, Hanley, Proc. Zool. Soc. Lond., 1844, p. 143.
Tellina valtonis, Hauley, in Sowerby's Thesaurus, vol. i. p. 283, pi. Ivii. fig. 68.
Tellina valtonis, Sowerby, Conch. Icon., vol. xvii. fig. 82 (narrow var.).
Tellina (Awjulus) valtonis, Eomer, Monogr. Conch. -Cab., ed. 2, p. 159.

Ha.bitat. — Levuka, Fiji Islands, in shallow water.

The locality of this species has not previously been recorded. The pallial sinus is
very large, reaching almost to the anterior scar. The line circumscribing it at first rises
some distance from the lower end of the hinder cicatrix, then descends obliquely and
more or less rectilinearly below the front scar, and finally falls subperpendicularly into
the pallial line beneath. The single specimen in the national collection is of a very pale
pink tint, whilst that obtained by the Challenger is very much deeper in tone, but the
pale rays at the posterior end are more conspicuous in the former than the latter.

Tellina verncdis of Hanley is closely allied to this species, being similarly sculptured
and very like in colour, except that the posterior pale rays are wanting. It is, however,
broader at the anterior end, and less acuminate behind. The hinge and pallial sinus are
the same.

Tellina (Angulus) lux, Hanley, var. ■

Tellina Tux, Hanley, Proc. Zool. Soc. Lond., 1844, p. 140.

Tellina lux, Hanley, Sowerby's Thesaurus, vol. i. p. 288, pi. Ivii. fig. 71.

Tellina lux, Sowerby, Conch. Icon., vol. xvii. fig. 286.

Tellina {Angulus) lux, H. and A. Adams, Genera Eec. Moll., vol. ii. p. 397.

Tellina {Angulus) lux, Romer, Conch. -Cab., ed. 2, p. 159.

Habitat. — Station 189, Arafura Sea, in 25 to 29 fathoms, and Torres Strait, in 8 to
1 1 fathoms (Challenger) ; Philippine Islands (Cuming).

The shells from the first two localities are not quite identical in fonn or colour with
that figured Ijy Hanley, but still, I have no doubt, belong to this species. The front
dorsal slope is not quite so oblique, the j)osterior scarcely so concave, and the hinder side-
margin is rather more arcuate. They are of a pinkish-white tint, with a pale pink ray
posteriorly. Tellina valtonis is very closely related to this species, having the same
hinge-dentition and pallial sinus, and distinguished principally by a slight difference of
form atj^the hinder extremity.

Tellina [Anyulus) natalensis, Krauss.

Tellina natalensis, Krauss, Siidafr. Moll., p. 3.
Tellina natalensis, Philippi, Abbild., vol. ii. p. 91, pi. iv. fig. 4.
Tellina natalensis, Sowerby, Conch. Icon., vol. xvii. fig. 280, a, b.
Tellina natalensis, Romer, Monogr. Conch. -Cab., ed. 2, p. 161.

Habitat. — Simon's Bay, Cape of Good Hope, in 1 5 to 20 fathoms

EEPOllT ON THE LAMELLIBRANCHIATA. 103

There are also specimens of this sj)ecies in the British Museum from the above
locality dredged during the voyage of the " Eattlesnake " in 7 fathoms on a sandy
bottom. The Challenger specimens are concentrically zoned with pink and cream colour,
intermingled here and there with narrow diaphanous stripes, and again others are
destitute of the pink bauds. On the other hand, the " Eattlesnake " examples are pinkish-
red, in some instances paler than others, or totally white, and at times varied with a few
pale rays, like the typical form described l)y Krauss.

Telliiia [Angulus) vernalis, Hanley.

Tellina vernalis, Hanley, Proc. Zool. Soc. Lond., 184-1, p. 111.

TelUna vernalis, Hanley, in Sowerby's Thesaurus Concli., vol. i. p. 289, pi. Iviii. fig. 84.

Tellina vernalis, SowerLy, Conch. Icon., vol. xvii. fig. 284.

Tellina {Awjulus) vernalis, Romer, Conch. -Cab., ed. 2, Jlonogr. Tellina, p. 159.

Tellina {Angulus) vernalis, H. and A. Adams, Genera Moll., vol. ii. p. 397.

Habitat. — Amboina, in 15 to 20 fathoms (Challenger) ; Singapore (Hanley).

This species is not quite so flattened as Tellina lux, rather more oblong, and has a
shorter and less concave ligamental sloj)e. It is perhaps also a trifle thinner, but has a
similar hinge, and the muscular scars and pallial sinus are very nearly alike in both
species. Tellina unifasciata, Sowerby, is also closely allied to the two species \mder
comparison, but is narrower and more acuminate behind than either.

Tellina [Angulus'?) 7'homhoides, Quoy and Gaimard.

Tellina rhomhoides, Quoy and Gaimard, Voy. " Astrolabe " Zool., vol. iii. p. 502, pi. Ixxxi. figs. 4-7.
Tellina rhomboides, Hanley, in Sowerby's Thesaurus, vol. i. p. 304, pi. Iviii. figs. 92, 96, 97.
Tellina rhomhoides, Sowerby, Conch. Icon., vol. xvii. fig. 114, «, h.
Tellina {Angulus) rhomboides, Etimer, in Couch.-Cab., ed. 2, p. 144, pi. xxxi. figs. 14-17

(magnified).
Tellina dathrata (Quoy), Deshayes, Hist. Anim. sans Vert., ed. 2, vol. vi. p. 208.
Tellina dathrata, Hanley, Cat. Rec. Biv. Shells, p. 65 ; Suppl. pi. xiv. fig. 12.
■Tellina {Peronella) imra, H. Adams, Proc. Zool. Soc. Lond., 1870, p. 789, pi. xlviii. fig, 6.
Tellina texlurata, Sowerby, Conch. Icon., vol. xvii. pi. xli. fig. 233, pi. xlv. fig. 233«.
Tellina lauta, Gould, Wilkes' Explor. E.xped., vol. xii. p. 408; Atlas, figs. 51i-51ib ; Otia

Conch., p. 79.
Tellina compta, Gould, loc. cit., p. 406, figs. 575-5756 ; Otia Conch., p. 79.
Tellina silicida (Deshayes), Sowerby, Conch. Icon., vol. xvii. fig. 278, c, '/.
Tellina bifaria, Baird, in Brenchley's Cruise of the " Curagoa," p. 451, pi. xli. fig. 13.
Tellina caseus, Sowerby, Conch. Icon., vol. xvii. fig. 115.

Hahitat. — Cape York, North Australia, in 3 to 1 2 fathoms, and Levuka, Fiji Islands,,
in 12 fathoms.

This species is varialde somewhat as regards form and the fineness of the oblique
striae, but quite constant in tlie character of the hinge. This consists of two strongish
cardinal teeth in the right valve, the anterior being cleft at tlie top, and a single bifid one

104 THE VOYAGE OF H.M.S. CHALLENGER.

in the left, with generally, especially in young shells, a second very small oblique slender
one posterior to the other. The ligament-plates (nymphse) are moderately developed
and more or less obliquely roughly striate, and somewhat grooved lengthways. From
this desciption it will be seen that the hinge of this species coincides exactly with that
of P.sammohia. The pallial sinus is very deep, reaching almost to the anterior scar.
Tellina silicula, Deshayes, and TelUna compta, Goulrl, are absolutely identical in every
respect, and are more closely and more obliquely striated than some other forms of the
species. Tellina pura, H. Adams, and Tellina hi/aria, Baird, agree with one another in
colour, lacking the rosy rays of the two above mentioned varieties.

The distribution of this pretty shell is as extended as its colour is variable. Tt has
already been recorded from the Philippine and Mariana Islands, New Caledonia, and the
Gulf of Suez, and in the British Museum there are specimens from the Keeling and Fiji
Islands, and also Madagascar.

Tellina (Arcojyagia) pretiosa, Deshayes.

TeHina jnvtiosa, Deshaye?, Proc. Zool. Soc. Lond., 1854, p. 360.
Tellina pretiosa, Sowerby, Conch. Icon., vol. xvii. fig. 329.
Tellina costata, Sowerby, lor. cit., fig. 19-i.

Habitat. — Levuka, Fiji Islands, in shallow water (Challenger) ; Island of Ovalau,
Fiji, in 12 fathoms, sandy bottom (Brit. Mus.) ; Philippine Islands.

There is no Hkelihood of this charming species being confounded with any other. It
is well distinguished from all others by the beautifully scj^uamate costellse which adorn
the surface. These are somewhat variable in number and thickness, those (about forty)
in the type from the Philippine Islands being a little stouter and less numerous than
those of Fiji examples, the latter, in this respect, agreeing perfectly with the shell
figured by Sowerby as Tellina costata. Between these radiating ridges are very fine
concentric thread-like lirse, which pass up the sides of the former, and on the top are
produced into scale-like processes, so that the valves, especially near the umbones, have
a cancellated aspect. The colour is grey-white, varied with an opaque-white short ray at
the apex of the l)eaks. The interior is either pure white or faintly tinged with yellow
at the upper part. The texture of the shell is thin, so that the cancellated character of
the external ornamentation is distinctly visible within. The lateral teeth are rather
strongly developed on each side in both valves, each also having two cardinals. In the
right the posterior tooth is twice as large as the anterior, and is bifid, as is also the front
one in the left valve, in which the hinder tooth is inconspicuous in comparison with the
rest. The pallial sinus is not very large, extending only a little beyond the middle of
the valves. The outline at first ascends on leaving the sear, then descends obliquely,
and finally slants backwards, forming rounded angles where the direction changes.

The largest specimen is 17 mm. long, 12^ high, and 6^ in diameter.

EEPORT OX THE LAMELLIBRANCHIATA. 105

Tellina [Arcopagia) elegant issima, n. sp. (PI. IV. figs.' 3-36).

Testa tenuis, albida vel pallide flavescens, ad umbones opaco-albo tincta, paulo
infequilateralis, transversim ovata, antice valde rotundata, postice angustior, acutior.
Margo dorsi anticus leviter declivis et arcuatus, posticus paululum brevior, vix magis
obliquus, subrectus. Margo ventris convexus, posterius baud flexuosus. Valvse leviter
convexse, liris numerosis radiantilius tenuibus, alternatim majoribus, aliisque concentricis
graciUoribus concinne sculpta3 ; lunula parva, profunda, laneeolata, sublsevis ; area valva3
sinistr^e Isevis, concava. Dentes cardinales lateralesque prominentes, tenues.

This species is very fragile, and so thin that the external reticulation of the surface is
visible within the valves. It is a little inequilateral, broader and more rounded in front
than behind, whitish or very pale }ellowish excepting the tips of the umbones, which are
opaque white. The dorsal margin is almost equally sloping on both sides, scarcely curved
anteriorly, and almost straight behind. The lower or ventral outline is well curved, more
gently ascending posteriorly than in front, and not sinuated. The surface of the valves is
ornamented with a very fine network of delicate radiating thread-like lirae, which are
generally alternately finer and coarser and crossed by still finer concentric elevated lines, the
points of contact being a little thickened. The dentition of the hinge is almost precisely
the same as in Tellina pretiosa, Deshayes, and the pallial scar is also very similar.

Length 15^ mm., height 12, diameter G.

Habitat. — ^Torres Strait, in 3 to 11 fathoms.

From Tellina pretiosa of Deshayes, its nearest ally, this species is distinguished l)y
being less acuminate posteriorly, more finely cancellated, and more inequilateral. The
radiating costellse in the species under consideration are more numerous, but the con-
centric ones, which are not elevated into scale-like projections on crossing the others, are
fewer than in Deshayes' shell.

Tellina ( ?) donacina, Linn^.

Tellina donacina, Linne, Syst. jS^at., eJ. 12, p. 1118.

Tellina donacina, Montagu, Test. Brit., pi. xxvii. fig. 3.

Tellina donacina, Wood, Gen. Couch., pi. xlv. fig. 5.

Tellina donacina, Pliilippi, Enum. Moll. Sicil., vol. i. p. 24.

Tellina donacina, Hanley, in Sowerby's Thesavu'us, vol. i. p. 232, i)l. Ivi. fig. 12, and pi. Ixvi.

fig. 259.
Tellina donacina, Forbes and Hanley, Brit. Moll, vol. i. p. 292, pi. xx. figs. 3-4, PI. K, fig. i.
Tellina donacina, Jeffreys, Brit. Conch., vol. ii. p. 386, and vol. v. p. 187, pi. xli. fig. 4.
Tellina donaiina, Sowerby, in Eeeve's Conch. Icon., vol. xvii. pi. x. fig. 43.
Tellina donacina, Romer, Conch. -Cab., ed. 2, p. 26, pi. ix. figs. 8-12.
Tellina donacina, Bertin, Nouv. Arch. Mus. Paris, 1878, vol. i. p. 261.

Habitat. — Station 75, ofi" Fayal, Azores, in 450 fathoms ; volcanic mud.

(7.OOU CHALL. EXP. PART XXXV. — 1885.) Mm 14

10(3 THE VOYAGE OF H.M.S. CHALLENGER.

Dr. Grwyn Jeffreys has shown that this species ranges from the north of England to
the Mediterranean and Madeira, and is found fossil in the Coralline Crag and Sub-
appenine Tertiaries. A fact in connection with this species which, I believe, has not
Ijeen previously recorded, is the presence of a small internal ligament. This is especially
noticeable in young shells, and is placed oblitpely, as in the genus Scmele, behind the
cardinal teeth. Several other species also possess this feature, and among those
obtained by the Challenger Expedition may he mentioned Tellina tenuilirata, Sowerby,
Tellina diluta, n. sp., Tellina Jijiensis, Sowerby, Tellina casta, Hanley, Tellina languida,
n. sp., and Tellina tenuilamellata, n. sp. Two other species also have a portion of the
ligament internal, but located, not obhquely as in the above species, but immediately
beneath the beaks. These are Tellina semen of Hanley, and Tellina semitorta of Sowerby.

Although these forms differ from others in the genus in this respect, I do not deem it
advisable to propose for them at present a new generic or subgeneric section. The grada-
tions in form and general aspect from one genus to another are so slight that I feel convinced
that a series of species of Tellinidse could easily be got together which would clearly represent
a gradual transition from group to group, so that it would be impossible to demonstrate
where, on the one hand, Tellina proper, without any internal ligament, ended, and, on the
contrary, where Seniele, with a conspicuous internal cartilage, commenced. Similar
gradations in respect of form, solidity, and dentition are also discoverable, so that it
becomes quite a simple matter to graduate the forms of Ahra into the genus Semele.

Tellina ( ?) tenuilirata, Sowerby.

Tellina tenuilirata, Sowerby, Coccb. Icon., vol. xvii. fig. 219, a, b {non sp. 253).
Tellinu tenuilirata, Angas, Proc. Zool. See. Loud., 1867, p. 919.

Testa parva, alba (interdum rosea), concentrice tenuiter striata, valde insequilateralis,
oblonga, postice acuminata, antice acute rotundata. Margo dorsi anticus elongatus,
rectiusculus, vix descendens, posticus longe brevior, valde obliquus, subrectilinearis.
Margo ventralis leviter curvatus, postice levissime incurvatus. Umbones parvi, acuti,
circiter in -g- longitudinis siti. Dentes cardinales duo inajquales in valva dextra,
unicus triangularis in sinistra ; laterales elongati, graciles. Ligamentum internum
angustissimum, valde obliquum.

This species is moderately thin, white or pink, small, and sculptured with fine con-
centric lines of growth. It is nearly twice as long as high, very inequilateral, the small
acute beaks being located at about one-third of the entire length from the hinder
extremity. The anterior portion narrows slightly and is sharply rounded at the end,
the posterior side being much more acuminated and somewhat wedge-shaped. The front
dorsal margin is elongate, only a little oblique and straightish, the posterior much

REPORT ON THE LAMELLIBRANCHIATA. 107

shorter, also nearly rectilinear or feebly concave and mitcli more sloping. The lower
ovitline is only a little convex towards the anterior end, where it curves upwards, forming
together mth the down-curving end of the dorsal line a sharply rounded extremity. The
ventral margin is straight or even a little incurved towards the narrowed end, and only
slightly and gently ascending. The left valve has a single triangular subbifid cardinal
tooth situated just a little anterior to the tips of the umbones. In the right valve there
are two, whereof the hinder one is similar to that in the left, and placed immediately
beneath the beak, so that when the valves are closed it has a posterior position to that of
the left valve. The front tooth is smaller, narrower, and forms as it were the end of the
lateral tooth. The side-teeth are elongate and well developed, and especially noticeable
in the right valve, in front extending along the greater part of the dorsal margin. The
internal ligament is small, narrow, placed behind the cardinal teeth, and slopes backwards.
The pallial sinus is very elongate, extending almost as far as the anterior muscular im-
pression.

Length 11 mm., height G, diameter 2f.

Hahitat.- — Port Jackson, Sydney, in 2 to 10 fathoms; also Flinders Passage, Torres
Strait, in 7 fathoms ; and Levuka, Fiji Islands, in 12 fathoms (Challenger) ; Sow and Pigs
Bank, Port Jackson (Angas).

This interesting little species has all the external appearance of a Tellinella, but of
course is quite distinct on account of the hinge-characters. The white variety is appa-
rently more common than the rose-coloured, jiidging from the series of specimens at
hand.

A second species described by Sowerby in his monograph of Tellina under this name,
TelUna tenuilirata (Conch. Icon., species 253), is a large shell having much the form of
Tellina loerna, but differing in the character of the sculpture.

The specimens dredged in Flinders Passage and oif Levuka are smaller than typical
forms from Port Jackson, and are probably not full-grown. The latter series are very
like those from the coast of New South Wales as regards form, but rather more coarsely
striated, especially towards the hinder end. The shells from Flinders Passage are not
quite so elongate as the others, or hardly so acuminate at the posterior extremity, stiU I
believe it would be unwise to describe and name as distinct species forms presenting such
slio'ht differences.

Tellina ( ?) fijiensis, Sowerby.

Tellina fijiennis, Sowerbj', Conch. Icon., vol. xvii. fig. 300.

Testa transversim oblonga, antice rotundata, postice angustata et cuneata, compressa,
valde insequilateralis, nitida, concentrice confertim striata, interstitiis prope latus posticum
paulo elevatis, sublamelliformibus, dilute salmonea vel lactea, raaculis semipellucidis

108 THE VOYAGE OF H.M.S. CHALLENGED.

irregularibus aut pallidis vel sanguineis picta. Margo dorsi aiiticiis elongatus, liorizou-
talis, rectiusculus, posticus brevior, abrupte descendens, vix arcuatiis ; margo ventralis
dorsali anteriori subparallelus, antice adscendeus, postice interdum subsiuuatus. Umbones
aeuti, j^rominentes, postmediani. Dentes cardinales inajquales, duo in utraque valva,
laterales in utroque latere, cardinaliljus baud renioti. Ligamentum externum breve, in
fossa parva situm. Cartilage interna angusta, obliqua, postice inclinata. Sinus pallii
profundissimus, cicatricem anteriorem fere attingens.

This species is nearly twice as long as high, rather compressed, of an oblong form,
rounded anteriorly, narrowed and subacuminate behind. It is very inequilateral, thickish,
either of a pale salmon tint marked with irregular sanguineous spots and streaks, or
ojiaque white varied with similar markings of a pale semipellucid character. The front
dorsal margin is almost horizontal, faintly concave close to the umbones, then straightish
or very slightly excurved. The posterior is much shorter, a very little arched, especially
at the upper \)avt, and considerably oblique, forming at the extremity with the lower
outline a sharpish angle which is most conspicuous in the left valve. The ventral out-
line is rather straight at the middle, exhibiting the slightest indication of a sinuation
towards the hinder end, being considerably upcurved in front. The umbones are small,
acute, and a little produced. The hinge consists of two cardinal teeth and two laterals
in each valve, mth an internal and an external ligament. The cardinals in the right
valve are divergent from one another, with a triangular pit between them, the posterior,
being stouter than the other and somewhat cleft at the top. In the left valve the
anterior is the stronger tooth and also somewhat bifid, the hinder one being thin,
lamellar, and bordering the internal ligament. The lateral teeth are subequidistant and
well developed. The external ligament is situated in a short sunken area behind the
beaks, and consequently is very little if at all elevated aliove the margin. The internal
cartilage is narrow, olilique, and posterior to the cardinal teeth. The pallia! sinus is ver^"
deep, extending almost to the anterior muscular impression.

Length 10 mm., height 5-j, diameter 2-^.

Habitat. — Levuka, Fiji Islands, in 12 fathoms (Challenger); Island of Ngau, Fiji,
at a depth of 10 fathoms on a sandy bottom (British Museum) ; Lord Hood's Island, in
coral sand at low water (Cuming).

The elongate form of this species was probably the cause which induced Mr. Sowerby
to locate it in the genus .Tellina, but it might with equal propriety be included in
Semele.

Tellina diluta, n. sp. (PI. IV. figs. 7-71).

Testa oblonga, postice angustata et subacuminata, antice acute rotundata, valde
inasquilateralis, tenuis, nitida, alba aut flavescens, concentrice tenuissime striata, medio-

REPORT ON THE LAMELLIBRANCHIATA. 109

(iriter coiivexa. Margo dorsi auticus pai'iim oljliquus, subrectiliiiearis, vix excurvatus,
posticus brevior, valde declivis, prope umbones levissime concavus, dein convexiusculus.
Margo veutris late curvatus, postice subsinuatus. Dentes cardinales duo insequales in
utraque valva. Dentes laterales validi, elongati. Pallii .sinus angustus, profundus.
Ligamentum internum obliquum, angustum.

This species is small, thin, semipellucid, white or pale yellow, glossy and finely
concentrically striated, the striae being close and regular, and some of the interstices
towards the posterior end slightly elevated and lamellar. It is somewhat convex,
considerably inequilateral, of an elongate oval form, rather acuminate or shortly rostrate
behind and sharply rounded in front. The posterior dorsal slope is very oblique, slightlv
concave immediately behind the small acute beaks and then faintly excurved. The
anterior margin is much longer, almost straight, or very faintly arcuate at first, and
finally curving into the ventral margin forins an acutely rounded end. The lower
outline is broadly curved and indistinctly sinuated towards the hinder extremity. The
hinge is composed of two cardinal teeth in each valve, whereof the posterior in the right
and the anterior in the left are lari^er than the others and rather triangular. The
laterals are well developed, and the pallial sinus is deep, reaching within a short
distance of the anterior muscular impression.

Length 8 mm., height 5, diameter 2^.
, Habitat. — Station 185b, east of Cape York, North Australia", in 155 fathoms; coral
sand.

Tellina ( ?) casta, Hanley.

Tellina casta, Hanley, Proc. Zool. Soc. Lond., 1844, p. 63.''

Tellina casta, Hanley, Sowerby's Thesaurus, vol. i. p. 253, pi. Ivi. tig. 9.

Tellina casta, Sowerby, Conch. Icon., vol. xvii. fig. 269.

Tellina (Areopagia) casta, Ecimer, Monogr. Conch. -Call., eJ. 2, p. 95.

Habitat. — Torres Strait, in 3 to 1 1 fathoms (Challenger) ; Singapore (Hanley).

This species is described as inequivalve, and it is the left ^•alve whirli is a trifle more
convex than the right. The dorsal margins are correctly said to he " on either side
nearly straight, moderately and nearly equally sloping." From this description it will
be seen that Sowerby's figure is somewhat inaccurate, giving a too decided convexity to
the anterior slope. There are two diverging cardinal teeth in the right valve, the
posterior of which is much the larger and bifid, and the lateral grooves are strongly
marked on both sides. On the contrary, in the left valve the anterior is the larger of
the two, and likewise cleft. The ligament projects but verj- little, and a portion of it
forming an internal cartilage is situated in a narrow pit just behind the cardinal
teeth.

110 THE VOYAGE OF H.M.S. CHALLENGER.

Tellina ( ?) languida, n. sj). (PI. IV. figs. 8-8?^).

Testa parva, tenuis, alba, pellucide zonata, nitida, incrementi lineis tenuissime striata,
insequilateralis, ovata, postice acuminata. Margo dorsi auticus vix obliquus, levissime
convexus, posticus valde declivis, rectilinearis. Ventris margo antice arcuatus, postice
lente vix arcuatim adscendens. Umbones parvi, acuti, prominuli, postmediaui. Dentes
cardinales duo in utraque valva, quorum unus triangularis, bifidus. Dentes et fossae
laterales graciles, remoti. Ligamentum parvum, partim internum. Sinus pallii per-
magnum, profundum.

This species is very like Tellina casta with regard to sculpture, colour, and the
character of the cardinal teeth and ligament. It is, however, of a different form. It is
decidedly more inequilateral, has the anterior end higher and more broadly rounded, the
dorsal slope on that side less straight, and the posterior end more acuminate. The lateral
teeth are also more remote and less pronounced. It is of an irregular ovate form,
narrowed and pointed behind. It is considerably inequilateral, glossy, finely concentri-
cally striated, moderately convex, white varied with a few semitransparent zones. The
front dorsal margin is a very little convex and only slightly oblique, the j)osterior being
almost rectilinear and very slanting. The lower outline is broadly arcuate, more rajiidly
upcurving in front than posteriorly, where the ascent is straightish, scarcely incurved.
The umbones are small, acute, a little elevated and worn at the extreme tip. The pallial
sinus is very wide and deep, and extends three-fourths of the way across the valves.
There are two cardinal 'teeth in each valve, whereof the posterior in the right and the
anterior in the left are much stouter than the others, and liifid.

Length 9 mm., height 7, diameter 4|^.

Habitat. — Torres Strait, in 3 to 11 fathoms, and Flinders Passage, in 7 hithoms.

Tellina ( ?) tenuilamellata, n. sp. (PL IV. figs. 9-9/>).

Testa rotundata, asquilateralis, tenuis, semipellucida, alba, lineis ojjacis albis radian-
tibus tenuissimis disjunctis oruata, antice regulariter curvata, postice paulo angustior,
lamellis angustissimis concentricis instructa. Margo dorsi utrinque declivis, leviterque
convexus. Margo ventralis late arcuatus, posterius vix sinuatus. Umbones ad apicem
plerumque erosi, aliquanto prominentes. Dentes cardinales duo in utraque valva, postice
valvae dextrse valde bifido. Laterales conspicui, anteriori cardinalibus subapproximato.

This species is a little longer than high, rather roundish, well rounded in front and
indistinctly pointed behind. It is very thin, fragile, and semitransparent, so that the
external sculpture and markings are seen through on the inner surface. It is almost
equilateral, whitish, or faintly tinged with yellow, ornamented with excessively fine

REPORT ON THE LAMELLIBRANCHIATA. Ill

iuterrupted radiating opaque white lines which are visible to the naked eye. The
sculpture consists of verj^ thin narrow concentric lamellse, and extremely fine interA'ening
concentric striae, whicli, liowever, are only to be seen with the aid of a compound
microscope. The umbones are k little prominent, and in the three valves under
examination worn away at the extreme apex. The dorsal margin is somewhat oblique on
botli sides, a little arcuate in front, but rather straighter behind. The lower outline is
well curved, exhibiting only the faintest indication of a posterior sinuation. The hinder
cardinal tooth of the right valve is deeply cleft, and the lateral teeth are well developed,
the anterior being rather nearer the apex than the posterior. The internal ligament is
small, narrow, and located obliquely against the hinder cardinal tooth of the left valve,
in the right being separated from the posterior tooth by a narrow pit which receives the
corresponding tooth of the other valve. The muscular scars and pallial sinus are very
indistinct, as is often the case in thin shells.

Length 9 mm., height 7-|, diameter 4^.

Habitat. — Station 188, south of New Guinea, at a depth of 28 fathoms ; green mud.

The valves here described are not probably full grown, but are sufficiently peculiar to
warrant their description.

Tellina ( ?) semen, Hanley.

Tellina semen, Hanley, Proc. Zool. Soc. Lond., 1844, p. 164.
Tellina semen, Hanley, in Sowerby's Thesaurus, vol. i. p. 249, pi. Ivi. fig. S.
Tellina semen, Eomer, Conch. -Cab., ed. 2, p. 9.5 {non Tellina semen, Sowerhy, Conch. Icon.,
vol. xvii. fig. 232).

Habitat. — Flinders Passage, in 7 fathoms, and Station 187, near Cape York, Torres
Strait, in fi fathoms ; also Levuka, Fiji Islands, at a depth of 12 fathoms.

The locality of this species has not, I believe, been hitherto recorded. Tellina.
semitorta, Sowerby, is closely allied, being very similarly sculptured, but of a rather more
elongate form. The shell figured by Sowerby as Tellina semen is, on the contrary, too
short and too high for the present species. Both of these forms have a small internal
ligament immediately beneath the umbones, showing an approach to the genus Semele.

Tellina ( ?) semitorta, Sowerby.

Tellina semitorta, Sowerby, Conch. Icon., vol. xvii. figs. 221, a, h.
Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

This species is elongate, rather Donaciform, very inequilateral, moderately convex,
equivalve, white, marked with very fine irregularly radiating, interrupted and wrinkly
pellucid lines which are invisible to the naked eye. The front dorsal margin is very long,
only slightly sloping and almost rectilinear. The posterior is only about half as long,

112 THE VOYAGE OF II.M.S. CHALLENGER.

very oblique, and also very little excurved. The ventral outline is very gently arcuate,
upcurving at both ends, forming rounded extremities. When the shell is viewed with
the posterior end towards the eye the lower edges of the valves are seen to l^e slightl}'
tortuous near that part, whence the species has derived its name. The surface of the
valves is finely concentrically striated, the sculpture at the hinder part being somewhat
finer than in Tdlina semen of Hanley. The ligament is short, yellow, and prominent.
The anterior lateral teeth and the plate supporting the ligament are tinged with pale red,
the corresponding parts in Tellina semen being white. The pallial sinus is large, deep,
rounded at the end, and reaches almost to the front muscular scar.

In Sowerby's figure 221, a, the anterior dorsal slope and the ventral outline are rather
too convex, so that the form appears somewhat too short.

The types of this species, liljerally presented to the national collection by Mr. G. F.
Angas, were dredged in Watson's Bay, South Wales.

Family D o N a c i D M.

Donax, Linne.
Donax nitidus, Deshayes.

Donax nitida, Deshayes, Proe. Zool. Soc. Lond., 1854, p. 350.
• Donax nitida, Eeove, Conch. Icon., vol. viii. fig. 34.
Donax nitidus, Eomer, Concli.-Cab., ed. 2, ji. 51 {no7i. Donax nitidus, Sowerby, Thesaurus,
vol. iii. p. 314, pi. cclxxxii. fig. 75).

Habitat. — Port Jackson, Sydney, in 6 to 15 fathoms, and Station 187, near Cape
York, North Australia, in 6 fathoms.

This species was originally described from specimens said to have been collected at
Moreton Bay. It is well characterised by its slender form, its smooth glossy surface, and
the conspicuous coarse arcuate sulci and intermediate ridges down the posterior end.

These do not extend c^uite to the dorsal margin, thus leaving a smooth lanceolate area,
which does not, howevei", extend to the posterior extremity of the shell. Although the
valves appear smooth and glossy to the naked eye, they nevertheless are ornamented
with excessively fine radiating white substrise, such as ol)taiu in many species of the genus.
The colour of this species is white, varied with two short livid l)rown rays and a brownish
stain upon the sulcated end of the valves. These markings are also faintly visible within
the valves, which are otherwise white inside and finely denticulated along the fainth^
ourved ventral margin. M. Deshayes described this species as totally white, -with the
exception of a pale violet flesh-coloured lunule. This is not, however, correct, either as
regards the types in the Cumingian collection or the Challenger specimens, all of which
exhibit the rays above mentioned.

REPORT ON THE LAMELLIBKANCHIATA. ll:j

Family P E T i; i c o l i d ^.

Petricola, Lamarck.
Petricola la2ncida (Chemnitz) juv.

Venus lapicida, Chemnitz, Concli.-Cab., vol. x. p. 350, figs. 1604, 1665.

Habitat. — Flinders Passage, North Australia, in 7 fathoms; also Station 18(), off
Cape York, Torres Strait, in 8 fathoms.

Only one or two small valves were collected. At this early stage of growth the
peculiar sculpture of this species is very fine indeed. Its occurrence in Torres Strait
and its distribution have been already recorded by the author iu the Report on tlie
"Alert" collections, p. 98.

Venerupis, Lamarck.
Venerupis irus (Linn^).

Donax iruK, Linn^, Syst. Nat., ed. 12, p. 1126.

Donax irus, Donovan, Brit. Shells, vol. i. pi. xxix. tig. 2.

Venerupis irus, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 16-3.

Venerupis irus, Forbes and Hanley, Brit. Moll., vol. i. p. 156, pi. vii. figs. 1-3, and PL G. fig. 2.

Venerujiis irus, Jeffreys, Brit. Conch., vol. iii. p. 86, vol. v. pi. li. fig. 5.

Venerupis irus, Sowerby, Thesaurus, vol. ii. p. 763, pi. clxiv. fig. 1, and pi. clxv. figs. 31, 32.

Venerupis irus, Pfeiffer, Conch. -Cab., ed. 2, Monog. Veneracea, p. 245, pi. xxxi. figs. 17-19.

Venerupis irus, Sowerby, Conch. Icon., vol. xi.x. fig. 22.

Habitat. — Tenerife, Canary Islands, at a depth of 70 fathoms.

This well-known form has previously been recorded from the Canary Islands, and may
eventually be found still farther south. It does not aj^pear to range farther north than
some parts of England and Ireland. It has received many names, and to give the com-
plete synonymy and list of references would be useless ; this being only advisable when
a monograph is attempted.

Family Y e N e r i d .^.

Subfamily TAPESiN.iE.

Tai^es, Megerle.
Tapes obscurata, Deshayes.

Tapes obscurata, Deshajes, Ftoc. Zool. Soe. Lond., 1853, p. 9; Cat. Conchif. Brit. Mus., p. 169.

Tapes obscurata. Reeve, Conch. Icon., vol. xiv. fig. 12.

Tajyes grata, Deshayes, Proc. Zool. Soc. Lond., 1853, p. 9; Cat. Conchif. Brit. Mus., ji. 170.

Tapes similis, Reeve, (non Deshayes), Conch. Icon., fig. 10.

Tapes quadriradinta, Deshayes, Proc. Zool. Soo. Lond., 1853, p. 9; Cat. Conchif. Brit. Mus., p. 171.

Tapes quadriradiata, Reeve, loc. cit., fig. 6.

Tapes quadriradiata, Romer, Monogr., p. 51, pi. xviii. fig. 2.

Venus quadriradiata, Pfeiffer, Conch.-Cab., ed. 2, p. 199, pi. xxxii. fig. 6.

Habitat. — Amboina, in 15 to 20 fathoms (a single dead valve).

(zool. CHALL. EXP. PART XXXV. 18S5.) M Ul 15

114 THE VOYAGE OF H.M.S. CHALLENGER.

There appears to me little doiibt that the above so-called species are ])ut variations of
one and the same form. I do not find any distinguishing characters in the outline or the
sculpture, all are finely concentrically sulcate-striate towards the umbones, the grooving
becoming gradually stronger and further apart as the shell enlarges, especially towards
the hinder end of the valves. The posterior dorsal margin is well arched, curving into
the lateral outline without any perceptible angle. In addition to the concentric sculpture,
there are generally (not always) traces of faint radiating substrise, more or less visible
when the shell is viewed in certain positions. The colour-ornamentation may vary in
intensity and definition, but in general arrangement and character it is the same.
AU the varieties exhibit four more or less well-pronounced and interrupted rays, besides
a somewhat zig-zag reticulation of dark lines very indistinct in the type {Tapes ohscurata),
more apparent in the variety Tapes grata, and most conspicuous in the form named Tapes
quadriradiata.

The ornamentation of the lunule is fairly constant in all. It consists of short violet-
brown lines crossing transversely to the length. They do not extend beyond the
impressed circumscribing line, and consequently the lunule has a very clear definition.

The posterior dorsal area is also somewhat similarly marked, but not so distinctly,
the colour of the lineation being rather paler. The dark blotch or stain near the centre
of this portion of the surface, mentioned by Deshayes and Romer in their descriptions
of Tap)es quadriradiata, is also traceable in Tapes ohscurata and Tapes grata, although
unnoticed by the latter author, and indeed in all specimens there is a second smaller
blotch nearer the umbones. Tapes similis of Deshayes ( = Tapes grata of Eeeve and
Romer) I regard merely as a small, finely sculptured form of the West African Tapes
dura of Gmelin. The Tapes ohscurata of Romer does not apparently belong to the
present species, nor do I consider his Tapes similis the same as Tapes grata, Deshayes.

Reeve in his monograph of this genus reversed the names of these two last species,
his Tapes similis being in fact the type of Tapes grata, and his fig. 9 representing the
true Tapjes similis. This confusion has no doubt misled Romer in his identifications.

Tapes [Paratapes) textrix (Chemnitz).

Venus textrix, Chemnitz, Conch.-Cab., vol. vii. p. 48, pi. slii. fig. 442.

Tapes textile, (Gmelin) Sowerby, Thesaurus, vol. ii. p. C81, pi. cxlvi. figs. 26-28.

Tapes textrix, Eeeve, Conch. Icon., vol. xiv. fig. 3.

Tapes textrix, Eomer, IMonogr., p. 19, pi. v. fig. 1.

Habitat. — Port Jackson, New South Wales, in 4 to 18 fathoms.

Specimens from this part of the coast of Australia differ slightly from Indian Ocean
examples in the style and tone of the painting, agreeing better with Tapes undulata
than with Tapes textrix. The upper part of the valves is of a pale yellowish-brown tint

REPORT ON THE LAMELLIBRANCHIATA. 115

varied with very little of the network markings which occur in both forms. Towards the
outer margin, however, they are more prevalent and of the same violet colour as in Tapes
undulata. The luuule also in these Port Jackson specimens is narrower than in typical
examples of Tapes textrix, the dark red-brown lines upon this part and the dorsal area
being likewise less vivid. Another feature in which they difier from the typical form is
in the margins of the valves being thinner, in this respect more resembling Tapes undulata
than Tapes textrix, the latter having peculiarly smooth and much thickened edges. Thus
it will be seen that the shells under examination in some characters are very like Bora's
species, still they have not the slightly oblique striae upon the middle of the valves,
which is so characteristic a mark of that form, nor are they c[uite so narrow at the
extremities.

Tapes textrix is found on the Malabar coast (Chemnitz), Andaman Islands (E.
Hamilton, in Brit. Mus.), and probably other places in the Indian Ocean.

Tapes (Paratapes) undid ata (Born).

Venus undulata. Born, Test. Mus. Csesar. Vindobon., p. G7.
Tapes undulata. Reeve, Concli. Icon., vol. xiv. fi;,'. 8.
Tapes {Textrix) •undulata, Romer, Mouogr., p. 20, pi. v. fig. 2.
Verms rimosa, Philippi, Abbild., vol. iii. p. 77, pi. vii. fig. 7.
Tapes rimosa, Sowerby, Thesaurus, vol. ii. p. G82, pi. cxlvi. fig. 29.

Habitat. — Station 189, Arafura Sea, in 25 fathoms; also Station 233a, off Kobe,
Japan, in 8 to 50 fathoms.

This species has already been recorded from Japan and China, and in the British
Museum I find specimens collected at Ceylon by E. W. H. Holdsworth, Esq. Although
closely resembling Tapes textrix it is well distinguished by the difference of sculpture.

Tapes [Paratapes) semirugata (Philippi).

Venus semirugata, Philippi, Abbilil., vol. iii. p. 76. ])1. vii. fig. 4.
Tapes seiniruijata, Sowerby, Thesaurus, vol. iii. p. 681, pi. cxlv. fig. 12.
Tapies (Textrix) semiruijata, Rdruer, Monogr., p. 29, jil. ix. hg. 1.
Tapes imlita, Sowerby, loc. cit., p. 682, pL cxlv. figs. 15, 16.
Tapes polita, Reeve, Conch. Icon., vol. xiv. fig. 49.

Habitat. — Station 188, south of New Guinea, in 28 fathoms, on a mutl Ijottom.

The single specimen from this locality agrees in all respects with Komer's
admirable description, but has the four interrupted rays rather more decided than in
the specimen he fig-ures. Tapes 2Jolita of Sowerby is merely the younger state of

116 THE VOYACxE OF H.M.S. CHALLENGER.

this species, iu which the concentric sulci are only beginning to develop. The brown
apices to the umbones referred to by him are probably characteristic of this species, as I
find them in the specimen before me.

Sowerby observes that the " inside is orange under tlie umbones and marked with
grey near the margin."

On examining tlie type of his species I find the colour beneath the beaks is
scarcely deep enough for orange, but should rather be called gamboge-yellow, and the
grey markings near the margin are the exterior zig-zag lines, which are not hidden by
an internal w^hite shelly coating as in adult shells. His specimen is said to have been
dredged near Sydney, at a depth of 6 fathoms, on a mud Ijottom.

Tapes {Amygdala) intermedia (Quoy and Gaimard).

Venus intermedia, Quoy and Gaimard, Voy. de I'Astrolabe, Mollusques, vol. iii. p. 526, pi.

Ixxxiv. figs. 9, 10.
Venu^ intermedia, Hanley, Cat. Biv. Shells, p. 127, Appendix, p. 358, pi. xvi. tig. 41.
Veniis largilliarti, Philippi, Abbild., vol. iii. p. 60, pi. ix. fig. 3.
Tapes intermedia, Sowerby, Thesaurus, vol. ii. p. 692, pL cxlvi. fig. 40.
Tapes intermedia, Reeve, Conch. Icon., vol. xiv. fig. 59.
Tapes intermedia, Hutton, Manual New Zealand Moll., p. 151.
Tapes {Amygdala) intermedia, Romer, Monogr., p. 83, pi. xxix. fig. 2.

Habitat. — D'Urville Island, New Zealand, on the beach.

This is a well-known species of a pale whitish-brown colour, and, according to Hutton,
common at the Auckland Islands.

Tapes [Amygdala) fahagella, Deshayes.

Tapes fabagella, Deshayes, Proc. Zool. Soc. Lond., 1853, p. 10.
Tayes fahacjella, Deshayes, Cat. Conchif. Brit. Mus., p. 182.
Tapes fahagella, Eeeve, Conch. Icon., vol. xiv. fig. 66.
Tapes fahagella, Romer, Monogr., p. 91, pi. xxxi. fig. 2.
Tapes fahagella, Hutton, Manual New Zealand Moll., p. 151.

Habitat. — Port Jackson, New South Wales, in 2 to 10 fathoms.

This species is also found at Lake Macquarie, New South Wales, and ofi" the
Tasmanian coast. Mr. G. French Angas, who is well known as the author of several
papers on the MoUuscan fauna of Australia, liberally presented specimens to the British
Museum, from the former locality, and the same institution is indebted to Mr. E. Gunn
for others from the latter. The original habitat, " New Zealand," assigned to this species
has not yet been confirmed, and it is somewhat doubtful wlictlifv it be correct.

REPORT ON THE LAMELLIBRANCHIATA. 117

Tapes {Amygdala) exalbida (Chemnitz).

Venus exalbida, Chemnitz, Conch. Cab., vol. xi. p. 225, pi. ccii. fig. 1974.
Vetiiis exallmla, Sowerby, Thesaurus, vol. ii. pi. clxi. fig. 193.
Venus exalbida. Reeve, Conch. Icon., vol. xiv. fig. 13.
Chione exalbida, Deshayes, Cat. Conchif. Brit. Mus., p. 154.

Habitat. — Station 316, off the east side of the Falkland Islands, in 4 to 5 fathoms ;
mud.

This species is also quoted as coming from the Strait of Magellan by Sowerby and
Eeeve. It attains a large size, measuring at times as much as 110 mm. in length. Young
shells are more squarely truncate posteriorly than full-grown examples, which become
almost suhrostrate at the extremity. The form of the luuule also alters from roundly
cordate in the young to broad lanceolate in the adult. Romer places this species in his
section of Venus which he has named Katelysia.

Subfamily Venerin^.
Venus, Linne.

Venus philomela, n. sp. (PI. II. figs. 7-76).

Testa ovata, in8ec|uilateralis, antice brevioi", alba, versus umbones interdum purpureo-
roseo tincta, concentrice tenuiter lirata. Lunula anguste cordata, linea impressa circum-
scripta. Umbones parvi, parum prominentes, ad apicem Iseves. Cardo dentibus tribus
in utraque valva instructus, in dextra postremo, in sinistra mediano bifido. Margo
valvarum intus minute denticulatus. Imprcssiones musculares irregulariter ovata?,
anteriori paulo angustiori. Sinus palUi par\ais, brevis, triangularis.

This shell is of a transversely ovate form, narrower in front than behind, moderately
thick and decidedly inequilateral, the apex of the beaks being situated at a point marking
ofi' three sevenths of the entire length of the shell from the anterior end. The latter narrows
to a somcAvhat sharply rounded extremity. The front dorsal slope is very oblique, rather
rectilinear at first, then gradually curving into the arcuate end. The posterior dorsal
margin is almost horizontal, nearly straight for some distance until it commences to
descend and curve, forming the broadly rounded lateral margin. The ventral outline is
widely arcuate, curving up equally at both ends.

The umbones are small, smooth, glossy, incurved and directed anteriorly. The
lunule is rather narrow, striated by the fine terminations of the concentric ridges which
are interrupted by a distinct impressed line or stria which limits the lunule. There is
scarcely any posterior dorsal area, it being very narrow, linear, nud not defined. The
hinge consists of three diverging teeth in each valve. Those of the right are unequal,
the front one being smallest, lamellar, subparallel with the margin of the valve, the

118 THE VOYAGE OF H.M.S. CHALLENGER.

ceutral one most elevated, triangular, the hindmost being nearly as large, posteriorly
oblique, and somewhat bifid at the top. In the left valve both the anterior and posterior
teeth are slender, the central one being stout and distinctly bifid. The concentric lirse
are very fine at first, gradually increase with the growth of the shell, are rather sharp
and up-turned so that they are rough to the touch, the finger being passed from the
umbo downwards. They attenuate at the sides, and number about thirty-three in a
specimen measuring 9 mm. in height. The muscular impressions are subequal, the
anterior rather narrower than the posterior, and situated a little lower down. The sinus in
the pallial sear is small and angular. The crenulation of the margin is so fine that it is
only just visible to the naked eye, and commencing in front beneath the umbones extends
all round except along the posterior dorsal sloj^e. The ligament is wanting in all the
valves obtained, but is probably small, judging from the remains and the groove wherein
it rests. The colour within and without is either totally white or more or less stained
with purplish-rose in the umbonal region.

Length 12^ mm., height 10, diameter Gf. Another specimen is 12 mm. long,
9^ high, and 6 in diameter. •

Habitat. — Nightingale Island, Mid South Atlantic, 100 to 150 fathoms.

This species recalls to mind the Venus gayi of Hupe, a Chilian and West Patagonian
species, which, contrary to that now described, has the hinder end more acuminate than
the anterior, the posterior slope more oblique, is rather more solid, has a more coarsely
creuulated inner margin to the valves, and less acute stronger concentric ridges. In
addition to these difi"erences there are others in the hinge, muscular scars, and pallial
sinus.

Venus torresiana, Smith (PI. III. figs. l-lc).

Venics torresiana, Smith, Eeport Zool. Coll. "Alert," p. 94, pi. vi. figs. M-M2.

Testa transversa, antice rotundata, postice subtruncata, alba, obsolete rufo radiatim
maculata, ad apices et lunulam rufescens, concentrice lirata, infer liras radiatim striata,
paulo inajquilateralis. Margo dorsalis anterior arcuatus ad fijiem lunulse leviter incisus,
posterior paululum obliquus, rectiusculus, postice subangulatus. Extremitas antica
rotundata, postica arcuatim subtruncata, latior, ventralis late curvata. Lunula elongato-
cordiformis, perspicue circumscripta, concentrice lamellatim striata. Area angusta,
striata. Lamellae concentricse antice et in medio liriformes, postice tenues, elevatse.
Dentes cardinales tres in utraque valva, in dextra posteriori, in sinistra mediano aliquanto
bipartito. Sinus pallii mediocris, triangularis. Margo internus valvarum concinne
denticulatus.

The form of this species is longer than high and somewhat inequilateral, the anterior
end being rather the shorter. TJie length increases much more than the height as the

REPORT ON THE LAMELLIBRANCHIATA. 119

shell enlarges. The front dorsal margin may be described as a little arcuate and inter-
rupted by a slight notch at the groove which circumscribes the lunule. The posterior
margin does not descend so much in young specimens, and is very nearly rectilinear.
The hinder extremity is somewhat squarish, very feebly rounded, forming an obtuse
angle above, and curving more gently into the ventral margin which is but little arcuate
in the middle. The umbones are only a little prominent, generally tinged with red, and
curved over towards the front. The lunule also is generally stained with light red,
especially anteriorly. It is of a longish heart shape, prominent and very distinctly parted
off from the rest of the surface by a groove which cuts through the concentric costellse,
the fine ends of which form the only ornamentation of the lunule. These costellse are
rather close together in some specimens and more remote in others, in front and upon
the central portion of the valves being in the form of fine rounded ridges and posteriorly
become lamellar, thin, and erect. The radiating striae are fine, cover the entire surface
with the exception of the lunule and the narrow posterior area. A few towards the
hinder extremity are rather closer together than the rest, and others at the opposite end
crossing the concentric ridges give them a crenulated aspect. The two front teeth in the
right valve slope towards the anterior end. Of these the anterior is the more slender,
lamellar, and subparallel with the outer margin of the valve, the other being more diver-
gent. The third tooth is considerably stouter, has a posterior inclination, is distinctly
bifid at the top and quite separated from the neighbouring tooth. In the left valve the
central one is much the stoutest, situated very slightly posterior to the apex of the umbo,
and also bipartite. The hindmost tooth is the smallest, thin, and almost bounds the
ligament. The front one is also rather thin, very divergent anteriorly from the central
tooth. The front muscular scar is elongate, subpyriform, and narrower than the posterior,
which is of a roundish pear shape. The pallial sinus is moderately deep, acutely rounded
at the apex. The crenulation of the margin within the valves is fine, especially at the
hinder extremity, whilst upon that portion which includes the lunule it is especially
coarse, and consists of elongate transverse denticles.

Length 7 mm., height 5^, diameter 3f.

Habitat. — Station 187, oti' Cape York, North Australia, in 6 fathoms ; coral mud.

Only young specimens of this species were obtained at the above locality, and the
dimensions given do not approach those of more adult examples in the British Museum
dredged by Dr. Coppinger of H.M.S. "Alert" at Thursday Island, Torres Strait. The
largest of these has a length of 19 mm., is 15 high, and lOi in diameter. The form alters
considerably with the growth of the shell. In the earlier stages the posterior end is
broader than the anterior and subtruncate, the hinder dorsal margin being also less
oblique than that in front. On the contrary, in more adult shells the hinder extremity
becomes even narrower than the front, and the dorsal slope on the latter side is hardly
so descending as that on the former.

120 THE VOYAGE OF H.M.S. CHALLENGER.

Venus ( Ventricola) casina, Liime.

Venus casina, Forbes and Hanley, Brit. Moll., pi. xxiv. figs. 1, 5, G.

Venus casina, Reeve, Conch. Icon., fig. 15.

Veims casina, Sowevhy, Tlies. Conch., pi. clx. figs. 177-180.

Hahitat. — Tencrife, Canary Islands, at a depth of 70 fathoms ; also Station 75, oft"
Fayal, in 450 fathoms.

Only a single small valve was dredged at the latter localit}'. Mr. MacAndrew
obtained this species at Porto Santo, Madeira, and it is found in the Mediterranean and as
far north as Norway.

Voms {Ventricola) effossa, Bivona.

Vemis effossa (Bivona) Philippi, Moll. Sicil., vol. i. p. 43, jjI. iii. fig. 20, vol. ii. p. 34.

Venus effossa, Deshayes, Cat. Conchif. Brit. ^lus., p. 100.

Venus {Chione) (^Ventricola) effossa, Ittimcr, j\Ial. Blatt., 1867, vol. xiv. p. 124.

Hahitat. — Teuerife, Canary Islands, in 70 fathoms ; also Station 75, oft' Fayal, Azores,
in 450 fathoms.

Only a few odd valves of very young shells were obtained at the latter Station. In
this immature condition they do not exhibit the characteristic sunken lunula.

Venus (Antigona) lyuerpcra, Linne, var.

Venus puerpera, Linne, Mantissa, p. .545.

Venus puerpera, Sowerby, Gen. Rec. and Foss. Shells, fig. 1.

Venus pueipera, Sowerby, Tlies. Concli., p. 703, pi. clii. fig. 1.

Venus j)ueipera, Eeeve, Conch. Icon., pi. iv. fig. 10.

Venus 2Merpera, Pfeiffer, Conck -Cab. , ed. 2, p. 145, pi. 10, figs. 4, 5.

Habitat. — Eeefs oif Tonga tabu, July 21, 1874.

The shells from this locality differ only from the typical form of the species in having
no purple stain within the valves at the posterior end. In the British Museum a speci-
men from the Andaman Islands varies in the same manner, and others from the Fiji
Islands and Torres Strait are intermediate with respect to this coloration, having only
two small purple marks near the muscular scar. A character which appears to be pretty
constant both in the type and this variety is the V-shaped purple mark upon the ape.x of
the umbones. This feature I also find present in Venus resticulata, Sowerby, Venus cBgrota,
Eeeve, Venus lacerata, Hanley, Venus magnijica, Hanley, and would probably be met
with in young fresh specimens of Venus soioerhyi, Deshayes, and Venus clathrata, Deshayes.
In Venus crispata, Deshayes, and Venus listeri, Gray, it does not aj^pear to be present,
judging from the few .sj^ecimens examined. All the above-mentioned forms have the

REPORT ON THE LAMELLIBRANCHIATA. 121

posterior dorsal area channelled in each valve, and the dextral one overlaps the left
posteriorly. All are more or less distinctly four-rayed, in some instances, as in Venus
magnijica and Venus resticulata, only towards the umbones. After comparing closely
these various forms, I am of opinion that no constant differences would be found whereb}'
they might be separated if a verj^ large series, say a thousand specimens from various
localities, were studied. Tliey appear to 1)e races, just as the genus Homo is represented
by numerous races. The typical Venus puerpera probably never attains the large size
of the variety Venus clathrata, yet an intermediate is seen in Venus listeri, so that a
large specimen of the latter and a small one of the former resemble one another, and in
fact are the same species. The wider and more lamelliform ril)s on the posterior side of
Venus listeri vary considerably, and I do not consider this sufficient to mark that form
as a distinct species, and it is even (juestionable whether Vemis multicostata, Sowerby,
from Panama, should l)e separated. The typical form of Venus magnijica is very
remarkable on account of the jJurplish tone of its external colouring, which in itself is
not a sufficient specific, difference, seeing how variable this form is in this respect. The
form of the shell may vary from neaidy globular to transversely quadrate-ovate, and the
pallial sinus is more acute in some specimens than others.

Venus (Antigona) lamellaris (Schumacher).

Antigona lamellaris, Schumacher, Essai, p. 155, jil. xiv. fig. '1.

Dosina lamarddi, Gray, Analyst, vol. viii. p. 308.

Venus lamarclcii, Reeve, Conch. Icon., fig. 39, a, h.

Venus lamarcMi, Pfeiffer, Conch.-Cab., ed. 2, p. 142, pi. viii. iigs. 10, 11.

Venus lamarclcii, Sowerby, Thesaurus, pi. cliii. figs. 20, 21.

Venus suhrostrata. Wood, Ind. Test. Suppl., p. 58, pi. ii. fig. 7.

Venus suhrostrata. Reeve, Conch. Syst., pi. Ixviii. fig. 4.

Venus nodjilosa, Sowerby, Thes. Conch., p. 708, pi. cliii. fig. 16.

Habitat. — Torres Strait, in 5 to 11 fttthoms.

This species has also l^een recorded from Japan, China, and Wide Bay, East Australia.

Venus (Anaitis) pap>hia, Linne, var.

Venus x^iphia, Linnc, Syst. Nat., ed. 12, p. 1129.

Venus pajAia, Reeve, Couch. Syst., vol. i. pi. Ixviii. fig. 1.

Venus paphia. Reeve, Couch. Icon., vol. xiv. pi. xix. fig. 89, and pi. xxiii. fig. 11G« (as Vemig

cypria, Sowerby).
Venus paphia, Sowerby, Thes. Conch., p. 720, pi. civ. fig. 61.
Vaius paphia, Pfeiffer, Conch.-Cab., ed. 2, p. 130, pi. vii. figs. 4-6.
Venus paphia, Carpenter, Report Moll. West Coast North America, 1864, p. 571.

Habitat. — St Vincent, Cape Verde Islands, in 7 to 20 fathoms (Challenger, and
J. Macgillivray in Brit. Mus.).

(ZOOL. CHALL. EXP. PAUT XXXV. — 1885.) Mm 16

122 THE- VOYAGE OF H.M.S. CHALLENGER.

The variety of this well-kuown West Indian species from the Cape Verde Islands
is not so prolonged and acuminate posteriorly as the normal form, the concentric ribs are
not so interrupted and lamellar behind, and the valves are ornamented with four brown
rays, three being the usual number. Venus cypria, Sowerby, from the west coast of
Central America, I regard as a variety of this species, and Venus varicosa of the same
author appears to be another form of it with the concentric ribs excessively thickened.

Venus (Chione) ccdophylla, Phdippi.

Venus calophylla, Philippi, Wiegmann's Archiv fiir Nat., 1836, vol. i. p. 229, pi. viii. fig. 2.

Venus calophiillu, Hanley, Cat. Rec. Biv., Append., j). 301, pi. xvi. %. 26.

Venits calophijlla, Reeve, Conch. Icon., pi. xxiiL fig. 114.

Venus calophylla, Sowerby, Thes. Conch., vol. ii. ji. 724, pi. clx. fig. 176.

Venus thiara, Sowerby, Gen. Eec. and Foss. Shells, fig. 3.

Veiius tliiara, Reeve, Conch. Sj'st., vol. i. pi. ixvii. fig. 3.

Venus (Anaitis) calophylla, Eomer, Mai. Blatt., 1865, vol. xii. p. 157.

Venus (CircompJialus) calojjhylla, H. and A. Adams, Genera, vol. ii. p. 422.

Vemis ciuningil, Sowerby, Thes. Conch., vol. ii. p. 725, pi. clvii. fig. 122.

Habitat. — Station 187, west of Cape York, North Australia,in 3 to 28 fathoms; Station
203, PhUijipine Islands, in 20 fathoms ; and Port Jackson, Sydney, in 4 to 18 fathoms.

This species is very variable in the number of the concentric lamellae. In a S23ecimen
from China there are only twelve, whdst in another of equal size from North-east Australia
there are as many as twenty-eight. Ven us cumingii certainly cannot be regarded in
any other light than as a mere variety. The extra rotundity in the type is in a great
measure due to its being a young shell, which if allowed to have arrived at maturity
would no doubt have prolonged the hinder end of the shell as is the case with this species.

Venus [Chione) foliacea, Philippi.

Venus foliacea, Philippi, Abbild., vol. ii. p. 107, pi. v. fig. 1.

Chione foliacea, Deshayes, Cat. Conchif. Brit. Mus., p. 122.

Venus thiara, Sowerby, Thes. Conch., vol. ii. p. 723, pi. clviii. figs. 125-130.

Venus thiara. Reeve, Conch. Icon., pi. xxiii. figs. 109, 110.

Chione retroversa, Deshayes, Cat. Conchif. Brit. Mus., p. 123.

Venus (Anaitis) foliacea, Romer, Mai. Bliitt., 1865, vol. xii. p. 160.

Habitat. — Stations 186, 187, and 189, all in the region of Torres Strait, North
Australia, at depths varying from 3 to 28 fathoms (Challenger) ; Japan, Port Curtis,
Queensland, Ceylon (British Museum) ; Eed Sea and Madagascar (PhUippi).

This species, although very closely related to Venus tiara (DUlwyn, auct.), may
perhaps be sufficiently distinguishable. The specimens figured by Sowerby and Eeeve
are remarkable for the development of the posterior lobe of the concentric lamellae, and

REPORT ON THE LAMELLIBRANCHIATA. 123

approacli very closely to Vemis calo2'>hyUa. Romer is wrong, in my judgment, in
considering figs. 125 and 126 of the Thesaurus as representing Venus tiara.

Venus (Chione) jacksoni, n. sp. (PI.' III. figs. 2-2e).

Testa transversim ovata, utrinque aliquanto acuminata, vakle inaequilateralis, medio-
criter compressa, lamellis paucis valde distantibus tenuibus hie illic spinosis instmcta,
incrementique lineis striata, livido-fuscescens, radiis duobus angustis albis, postice
incHnatis, aliis latioribus antice ornata. Margo dorsalis posticus elongatus, late arcuatus,
paululum obliquus, anticus longe brevior, valde oblique descendens, levissime concavus.
Latus anticum acute rotundatum, posticum inferne productum, magis acuminatum.
Margo ventralis late curvatus, postice leviter subsinuatus, intus minute crenulatus.
Lunula lauceolata, fuscescens. Dentes cardinales tenues, divergentes. Sinus pallii
elongatus, linguseformis. Impressiones museulares parvse, subpjTiformes. Pagina
interna fuscopurpurea, versus marginem albida, iu medio radio albo bijjartita.

The form of this species is irregularly ovate, acuminate at both ends, especially behind.
The anterior slope is straightish or a little incurved at the lunule, and much more descend-
ing than the hinder dorsal margin. This is broadly curved at first, suljsequently descend-
ing more abruptly, and ^\'ith the ventral margin forms a rather acutely rounded angle.
The lower edge is widely arcuate in front, but towards the hinder extremity becomes
indistinctly sinuated, a feature best seen within the valves. The exterior of the valves
is finely striated by the lines of growth, and in addition bears a few very remote con-
centric ribs. These are thin and curved over towards the umbones, except where they are
produced into spine-like prolongations. These are four iu number upon each rib, erect,
hollow above, and situated one above the other so as to form four radiating series,
three of them having a posterior inclination and the fourth near the anterior margin.
The beaks are rather small, not quite adjacent, and situated at a point which marks off"
about three-elevenths of the entire length of the shell from the anterior end. The lunule
is narrow, three times as long as wide, of a brown colour, and circumscribed by an
impressed stria. The area is somewhat sunken, margined at first by a rounded ridge
on each valve which subsequently becomes less apparent. In the right valve the teeth
are three in number and rather fine. The hindmost is elongate, diverges from the apex
of the umbo, and runs parallel \\dth the ligament. The two others are in the same line
with each other, near together, and fall almost perpendicularly from the beak. Parallel
with and close to the front marain there is a Ions narrow oroove extending; the length of
the lunule which receives the acute edge of the opposite valve. Within the hinder
margin, beyond the ligament, there is a similar furrow, also for the reception of the sharp
margin of the left valve. In this there are two teeth, the anterior slender, the posterior

124 THE VOYAGE OF H.M.S. CHALLENGER.

large and much divided above, almost forming two teeth. The ligament is brownish-
yellow, small, not prominent, a little longer than the lunule. The muscular scars are
subequal, the front one a trifle the smaller, and the pallial sinus is deep, tongue-like
in form, parallel witli the venti'al margin, and extends half-way across the valve, just
reaching the central white ray. The colour of this species may be said to consist of
brown and white rays of different widths, the former colour predominating. One of the
white rays is especially remarkable, bisecting the valves in two nearly equal portions, and
within them is still more conspicuous as it passes through the purple-brown patch which
stains the upper part of the interior. The crenulation of the margin is very minute, and
extends only along the lower and posterior edges, the two dorsal slopes being quite smooth.

Length 26 mm., height 19^, diameter 11.

Habitat. — Port Jackson, Sydney, 4 to 18 fathoms (Challenger) ; Broken Bay, New
South Wales, on the sandy beach (in the British Museum, collected during the voyage of
the "Rattlesnake" in August 1847).

Venus [Chione) ovata. Pennant.

Vemis ovata, Peniuint, Brit. Zool., p. 206, pi. lix. fig. 3.

Venus ovata, Forbes and Hanley, Biit. Moll., vol. i. p. 419, pi. xxiv. fig. 2, pi. xxvi. fig. 1, and

pi. I. fig. 6 (animal).
Vemis ovata, Sowerby, Thesaurus, p. 718, pi. clvii. figs. 99, 100.
Venus ovata, Kecve, Conch. Icon., figs. 137, a, l>.

Habitat. — Station 75, off the Azores, at a depth of 450 fathoms ; volcanic mud.
This species ranges from Norway to the Mediterranean.

Vemis [Chione) scabra, Hanley.

Venus scahra, Hanley, Eecent Biv. SheUs, p. 361, pi. xvi. fig. 24.

Venus scahra, Sowerby, Thes. Conch., p. 718, pi. clvii. figs. 101, 102.

Venus scabra. Reeve, Conch. Icon., figs. 97, '/, b.

Chione scabra, Deshayes, Cat. Conch., p. 130.

Venus (Chione) scahra, Rdmer, Mai. Bliitt., 1867, vol. xiv. p. 58.

Habitat. — Station 233a, Kobe, Japan, in 8 to 50 fathoms ; sand.

This species has also been recorded from the Philippine Islands and Australia.

Ve7ius (CJiione) striatissima, Sowerby.

Vemis striatissima, Sowerhy, Thes. Conch., vol. ii. p. 718, pi. clvii. figs. 103-105.

Venus striatissima, Eeeve, Conch. Icon., fig. 135.

Chione striatissima, Desliaye;*, Cat. Conchif. Brit. Mus., p. 131.

Cliiune striatissima, Ktimer, j\Ial. Bliitt., 1867, vol xiv. p. 59.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms ; and Station 1G2, off East
Moncoeur Island, Bass Strait, at a depth of 38 to 40 fathoms.

REPORT ON THE [.AMELLIBRANCHIATA. 125

Venufi (Chione) marica, Liunc.

Venus miirica, lAnni, Syst. Nat., eil. 12, p. 11.30.

Venus marica, Chemnitz, Conch.-Cab., vol. vi. figs. 282-284.

Venus marica, Sowerby, Thes. Conch., vol. ii. pi. dvii. fig.s. 107-110.

Venus marica, Reeve, Conch. Icon., vol. .\iv. fig. 104, a-r.

Habitat.- — Levuka, Fiji Islauds, iu .shallow water (Cliallenger) ; Ovalau and ^latuku,
Fiji, in 12 fathoms (Brit. Mus.) ; Philippine Islands (Cuming); Reunion (Deshayes) ;
Mauritius (Mobius).

This species is so well known that it is unnecessary to give further references than
those above mentioned. It must not, however, be mistaken for Veiius recognita, which,
although very like it at first sight, is perfectly distinct. Venus marica is more finely
costate, and has not the fine posterior radiating lirse of that species nor the frill-like
concentric lamelliB ; its internal margin is more coarsely denticulate, and the dorsal area
differently sculptured.

Venus [Chione) recognita, n. sp. (PL III. figs. 5— 5e).

Testa ovato-subtrigona, j)ostice aliquanto angustata, fere sequilateralis, albida, plus
minusve fusco vel rufo irregulariter (interdum subradiatim) picta. Yalvas mediocriter
convexEe, concentrice liratse, radiatimque costata?, granulatte, liris postice prope aream
breviter lamellatis, tenuibus, costis paucis ad latus anticum quam cseteris majoribus,
aliisque posterioribus aliquanto tenuoribus. Margo dorsi utrinque valde declivis, leviter
convexus, extremitatem posticam versus ssepe levissime sinuatus. Latus anticum late
rotundatum, j^osticum angustatum, subcuneiforme. Margo ventris late areuatus, postice
frequenter indistincte sinuatus. Lunula variabilis, elongato-cordata vel lanceolata, in
medio prominens, sulco angusto profunde circumscripta, fusco maculata, radiatimqiie
lirata. Area lanceolata, haud radiatim lirata, striis incrementi tenuibus solum
sculpta, maculis magnis fuscis plerumque picta. Pagina interna all)a, violaceo-fusco
irregulariter maculata, margine minute denticulato. Sinus pallii parvus, angustus,
brevis. Dens mediauus cardinis iu valva sinistra et duo posteriores valvaj alterae ad
apicem bifidi.

This species is almost equilateral, moderately convex, longer than high, triangularly
ovate, broadly roundish in front and somewhat acuminated posteriorly. It is whitish,
irregularly stained and spotted with reddisli-l)ro-mi, sometimes in the form of more or
less interrupted rays. The sculpture consists of concentric and radiating ridges which
are closely packed, and at the jwints of contact form rounded bead-like granules. A few

126 THE VOYAGE OF H.M.S. CHALLENGER.

of the radiating costse towards the lunula are thicker than the rest on the central part of
the valves, and others just in advance of the dorsal area are much more slender and not
granular, being crossed by the concentric ILrse which at this particular part rise into very
thin, frill-like lamellae. The dorsal margin descends very obliquely on both sides, is a
little arcuate, and near the hinder extremity generally exhibits an indication of a feeble
sinuation, which, together with a similar faint incurvation in the lower outline, gives this
portion of the shell a somewhat rostrate character. The lunule varies in form, in some
examples being lanceolate and in others longish heart-shaped. It is radiately-granulosely
ridged, concentrically striated, prominent along the middle, and enclosed by a narrow
deep groove. The area is comparatively smooth, without radiating Urpe, merely sculptured
with very fine striae of growth, and generally marked with largish brown cross-bars or
sjjots. The interior is white, variously stained with purplish or violet-brown. The
hinge is not very strong and narrow. The central tooth in the left valve and the two
posterior in the right are grooved or bifid at the top. The anterior scar is subovate, the
posterior broader, rounder. The pallial sinus is small, narrow, and sharply rounded at
the apex. The margin is very finely crenulated along the lower part, and most minutely
on the posterior and anterior slopes, remarkably so at the lunule.

Length 21-^- mm., height 16^, diameter 10.

Length 18 mm., height 15^, diameter 10.

Habitat. — Station 212, south of the Philippine Islands, in 10 to 20 fathoms; sand.

This species has a close resemblance to Venus maricu, Linn., and indeed was confused
with it by M. Deshayes when he named the Veneridfe in the National Collection. It is
distinguished from that species by its generally narrower posterior end, closer and
coarser beaded radiating costse and concentric ridges, the latter posteriorly forming
longer thin erect lamellae and not short scales as in Veims marica. In the latter the
dorsal area is sculptured with fine radiating granulose lirae which ai-e wanting in VeJius
recognita, in which species the denticulation of the margin is very much finer than in the
Linnean form. Venus costellifera, Adams and Reeve, is another closely allied species,
but has not the posterior lamellae of the present one, coarser crenulation on the margin,
particularly at the lunule, and is radiately ridged on the dorsal area.

Venus (CJiione) lionotu, n. sp. (PI. III. figs. 7— 7b).

Testa parva, inagquilateralis, alba, vel dilute rufescens, antice in medio aliquanto
acute rotundata, postice inferne subproducta, magis acute cui-vata, ad marginem
inferiorem late ■ arcuata, fortiter cancellata. Lunula magna, distincta, elongato-cordato,
liris tenuibus radiantibus circiter sex, incrementi lineis concentricis decussatis instructa.
Area insignis, subdiaphana, haud radiatim lirata, terminis obsolctis lirarum concentri-

REPORT OX THE LAMELLIBRANCHIATA. 127

carum ornata. Umbones promincntes, valdc incurvati, paulo ante medium siti. Denies
tres cardinales in utraque valva. Margo interior valvarum minute denticulatus.

The form of this shell is longer than high, and somewhat roundly trigonal. The
anterior slope descends more suddenly than the posterior, and is arcuate in the lunular
region, forming with the upcurvcd lower edge a sharply rounded end. The posterior
slope is well arched, and rounds into the ventral margin more suddenly but lower down
than the anterior. The exterior surface, with the exception of the hinder dorsal area,
is strongly cancellated with radiating and concentric ridges, the former being thicker
than the latter. There are about twenty of them in the earlier growth of the shell,
exclusive of those on the luuule. Of these a few down th(> posterior side are rather finer
and more approximated than the rest, which are broader than the interstices between
them. In addition to these twenty, as the ventral margin is approached, other finer inter-
calary costse are met with. One of these generally falls in each interstice between the
larger ones, and gradually tapering from the edge upwards disappears about the middle of
the valve. The concentric ridges are moderately thin behind, thicker and subnodulous
on crossing the anterior and central radiating costse, vary from about eight to ten in
number in the numerous valves under examination, and are generally fairly equidistant.
They are excessively slender at the sides, becoming almost obsolete upon the lunula and
the area. The hinge-teeth are three in each A'alve. In the right the anterior is
smallest, and not quite parallel with the lunular margin, the two others being subequal
and diverging, the hindermost being somewhat bipartite. In the left valve the hind-
most is the smallest, very slender, and bounds the ligament. The central tooth is the
largest, bifid, situated just under the apex of the umbo, and inclines posteriorly. The
front one is more slender, diverging, and directed anteriorly. The beaks are smooth,
glossy, hyaline, well incurved, and have a forward direction. Just within the posterior
dorsal margin of the right valve there is a shallow groove for the reception of a corre-
sponding small ridge in the opposite valve. The denticulation of the margin, commenc-
ing at the umbo in front, extends all round, except for a short distance along the
posterior dorsal edge, and is a trifle finer near the hinder extremity than elsewhere.
Pallial sinus short, angular.

Length 4^ mm., height 3|, diameter 2|. A variety from Amboina with more
slender radiating costellse has a length of 3^ mm., is 3 high and 2^ in diameter.

Habitat. — Station 188, south of New Guinea, depth 28 fathoms, green mud ; variety,
Amboina, 15 to 20 fathoms.

The cancellation of the surface of this minute species is very coarse for the small
size of the sheU, and much stronger than that which obtains in the earlier stages of
growth of some of the well-known larger species from the same and neighbour-

ing seas.

128 THE VOYAGE OF H.M.S. CHALLENGER.

Venus (Chione) infans, u. sp. (PI. III. figs. 3-36).

Testa parva, rotuude subtrigonalis, insequilateralis, teuuiter cancellata, alba, interdum
fusco obsolete bi-radiata, antice late arcuata, postice angustior, subproducta. Lunula
magna, prominens, fusco tincta, elongato-cordata. Area indistincta aliquando
fuscescens. Dentes cardinales tres in utraque valva. Margo valvarum intus denticul-
atus, postice minutissime.

This shell is somewhat triangular, the angles being rounded, about as high as long,
with a cancellated surface. The cancellation consists of strong radiating ridges, of which
those upon the lunule and a few near the j^osterior slope are finer than the rest. These
are crossed by regular subequidistant fine concentric lamella having a crenulated aspect,
and being but little elevated. The lunule is large in proportion to the small size of the
shell, somewhat bulging, distinctly defined, and probably in most instances stained with
light brown, especially at the front part. The umbones are rather prominent, well
incurved and a little anterior in position. The hinge is composed of three teeth in each
valve. Of those in the right the anterior is the smallest, the others being subequal and
diverging. The central in the left valve is short, stouter than the anterior, located just
beneath the umbo, and inclines a trifle towards the hinder end. The anterior tooth is
more slender, diverging much towards the front, being subparallel with the margin, the
posterior being still thinner. The posterior dorsal margin in the right valve is grooved
to receive a prominent ridge in the left. The denticulation of the margin is coarse along
the lunule, fine immediately beneath and at the posterior extremity, and again more
strongly developed along the ventral portion. The interior of the valves is glossy, and
exhibits the pattern of the exterior cancellation, but only indistinct traces of the muscular
scars and pallial sinus are discoverable.

Length 4 mm., height 3f , diameter 2^. Another specimen is 3^ mm. long and 2f high.

Habitat. — Station 187, a little to the west of Cape York, North Australia, at a depth
of 6 fathoms. Also Station 188, a little further west, at a depth of 28 fathoms.

Several odd valves of this pretty species were dredged at the above localities, but
mostly in a dead chalky condition. In such as are fresh, the colour is more or less trans-
parent white, varied with two light brown rays down the central portion of the valves,
the lunule and hinder dorsal slope being sometimes tinged with the same colour. The
form of the species is high, and the cancellation of the surface comparatively strong,
corresponding in this respect with Venus stutclthuryi of New Zealand.

Venus (Chione) levukensis,n. sp. (PI. III. figs. 6-66).

Testa insequilateralis, alba, radiatim crassecostata, umbones versus laevigata, inter
costas sub-distanter concentrice striata, postice oblique subtruncata, antice angustior,

REPORT ON THE LAMEELIBRANCHIATA. 120

rotundata. Margo dorsalis anterior \al(lc declivis, leviter arcuatus, posticus minus
obliquus, aliquanto curvatus, ventralis late arcuatus. Lunula mediocris, distincta,
incrementi lineis fortibus striata, costa radianti, quam cseteris minori, circumdata.
Dentes cardinales tres in vulva dextra, divergentes ; anterior parvus, angustus, antice
directus, medianus erectus, crassior, sub apice umbonis situs, posticus maximus, retror-
sum iuclinatus. Margo valvarum intus minutissime denticulatus.

The length of the shell is a trifle greater than the height. It is white, inequilateral,
the anterior end being the shorter and somewhat sharply rounded, the hinder extremity,
on the contrary, being obliquely subtruncate, terminating in a rounded angle towards the
lower part. The dorsal margin is very oblique in front and only feeljly arcuate, pos-
teriorly it is almost horizontal, and likewise but little arched. The ventral outline is
broadly curved, ascending rather more anteriorly than at the opposite extremity. The
exterior surface of the valves is ornamented with strong radiating ribs, which, attenuating
from the margin upwards, become obsolete towards the umbones. They are about
eighteen in number, rounded, about as broad as the grooves between them, subequal in
thickness with the exception of a slender one enclosing the lunule and three or four on
the posterior side, rather finer than the rest. The slender one in front and two or three
following ones are somewhat tvibercular, being crossed by elevated lines of increase. In
the deepish furrows between the costse there are numerous very fine but somewhat
distant slightly raised concentric lirse. The lunule is distinct, elongate heart-shaped,
marked with rather strong raised lines of growth and a little prominent down the
middle. The beaks are small, not much raised above the hino;e-line, incurved and
directed towards the front. The cardinal teeth are three in number in the risht and
probal)ly so in the left. They are separated and divergent. The central one is erect,
triangular, and situated perpendicularly beneath the apex of the umbo. The front one
is the narrowest, and inclines anteriorly ; the posterior is a trifle longer than the central,
but scarcely so thick, directed backward, and probal:>ly in well-preserved specimens is
somewhat bipartite at the top. The crenulation of the margin of the valves extends all
round excepting upon that portion occupied by the hinge-ligament. It i.-< exccssivel)^
fine, particularly upon the lunular and posterior edges. The muscular impressions and
the mantle-mark are too indistinct for description.

Length 6 mm., height 5.

Habitat — Off Levuka, Fiji Islands, at a depth of 12 fathoms.

This species has a cardium-like aspect, and is remarkable for the inconspicuous
character of the concentric sculpture, the strong radiating ridges, and the deep grooves
separating them.

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 17

loO THE VOYAGE OF H.M.S. CHALLENGEE.

Venus (Chione) mindanensis, n: sp. (PL III. figs. 4-4?>).

Testa subquadrata, auticc ab apicc oblique subtruncata, postice inferue producta et
paululum acuminata, valde insequilateralis, costellis radiantibus tenuil)U3 lirisquc concent-
ricis iniequalibus subdistaiitibus coucinne caucellata, sordide albida, versus umboues plus
miuusve rubesceus. Lunula elongato-cordata, bene defiuita. Area parva, linearis aut
nulla. Dentes cardinales in valva dextra tres, quarum postremus paulo maximus, alii
duo subparalleli, graciliores. In valva sinistra duo anteriores valde divergentes ; anterior
elongatus, lamellseformis, tertius posticus elongatus, gracilis. Impressio muscularis
anterior elongata, subpyriformis, quam posteriori paulo minor. Sinus pallii perbrevis.
Margo valvarum intus minute crenulatus.

The form of this species is that of an irregular quadrangle, of which the anterior slope,
in conjunction with the posterior dorsal margin, forms at the beak one angle which is
almost but not quite so acute as a right angle.

The posterior dorsal margin is only slightly oblique and arcuate, curving gently inti>
the lateral margin, which, together with the ventral edge, forms a somewhat sharply
curved extremity, rather low down. The anterior slope descends in an abrupt manner,
is gently convex, and rounds into the lower margin, rather less acutely than at the hinder
extremity. The umbones are fairly prominent, situated very forward, and are well
incurved. The lunule is distinctly defined by a deep stria, elongate-cordate in shape, and
sculptured with five or six fine radiating costellsB which, being crossed by the lines of
growth, become subgranulose. The radiating ridges which ornament the exterior surface
are fine, but not crowded, regular towards the umbones, but further down the valves other
intercalary ones are met with which are rather finer. A few of the costellse near the
lunule are a trifle stouter and more approximated than the rest. The concentric lirae ai'e
thin, crenulated by the radiating riblets, reflexed towards the beaks, especially anteriorly,
where they are appressed upon the ribs above. They appear to be comparatively further
apart during the earlier stages of growth, and become more numerovis and crowded as the
shell increases. They difter in thickness, and their number is variable. The hinge is not
powerful, and consists of three teeth in each valve. Of those in the right the hindmost is
slightly the strongest and subparallel with the ligamental groove, the two others, of which
the front one is the more slender, incline the oj)posite way, and are in a line with each
other and almost with the anterior slope. The anterior tooth of the left valve is lamellar,
subparallel with the margin, and elongate ; the central one located just beneath the beak,
is short, thicker, and slopes in the opposite direction, and the hindmost is very slender
and borders the ligamental groove. The dentic-ulation of the margin of the valves is
very minute, especially posteriorly.

Length 8 mm., height 7, diameter 4.

REPORT ON THE LAMELLIBRANCHIATA. 131

Habitat. — Station 201, off the west coast of the isLiud of Mindanao, Pliilippine
Islands, at a depth of 82 fathoms ; stones and graveL

Venus [Leukoma) australis, So\verl)y.

Venus australis, Sowerby, Proc. Zool. Soc. Lond., 1835, p. 22.

Venus midralis, Sowerby, Thesaurus, p. 719, pi. clvii. figs. Ill, 112.

Venus australis, Hanley, Recent Shells, p. 118, pi. xv. fig. 48.

Venus australis. Reeve, Concli. Icon., fig. 107, a, h.

Chione australis, Deshayes, Cat. Conchif. Erit. Mus., p. 142.

Venus {Chione) (Lcidfoma) aiisiralis, Romer, Mai. Bliitt. 1867, vol. xiv. p. 102.

Habitat. — Port Jackson, Sydnej', in 5 to 7 fathoms (Challenger) ; Swan River
(Deshayes).

Venus {Chamelcea) tnesodesma, Qnoy and Gaimard.

Venus mesodesma, Qnoy and Gaimard, Voy. " Astrolabe," vol. iii. (1834), p. 532, pL Ixxxiv.

figs. 17, 18.
Venus crassa, Quoy and Gaimard, loc <•!!., p. 525, pi. Ixxxiv. figs. 7, 8.
Venus denticulata, Quoy and Gaimard, loe. cit., p. 530, pi. Ixxxiv. figs. 14, 16.
Venus vinlacea, Quoy and Gaimard, Joe. cit, p. 533, pi. Ixxxiv. figs. 19, 20.
Venus sinssa, Deshayes, Anim. sans Vert., vol. vi. p. 373.

Venus spissa, Hanley, Cat. Biv. Shells, p. 117, Appendix, p. 358, pi. xvi. fig. 44.
Venus spurca, Sowerby, Proc. Zool. Soc. Lond., 1835, p. 23.
Venus spurca, Sowerby, jun., The.saurus, vol. ii. p. 719, pi. clvi. figs. 92-98.
Venus spurca. Reeve, Conch. Icon., vol. xiv. figs. 90, «, /'.
Chione mesodesma, Hutton, Man. X. Zeal. Moll., p. 148.
Ve7ms {CJtione, sect. Chamelwa) mesodesma, Rdmer, Mai. Bliitt., 1867, vol. xiv. p. 113.

Habitat. — D'Urville Island, New Zealand, on the beach ; also Station 135e, off
Tristan da Cunha, at a depth of 1000 fathoms. Hard ground, shells and gravel.

The localities " Valparaiso and the Philippine Islands," assigned to these species by
Sowerby and Reeve, reqnii'e confirmation. Two specimens from Tristan da Cunha, as
might be expected, differ slightly from the usual form of the species. They are of a
rather less triangular shape, the posterior side being rather broader than in New Zealand
examples, and the umbones are placed a trifle nearer the anterior end than in most
specimens. They are whitish, destitute of any brown markings, and in one instance
reddish at the umbones. With the exception of these few slight differences I cannot
discover any characters which could be regarded of sufficient importance to separate
specifically these two shells from this well-known and common New Zealand form.
Although far apart, the two localities are almost on the same parallel.

132 THE VOYAGE OF H.M.S. CHALLENGER.

Venus (Gomphina) nndulosa, Lamarck.

VcnHn undidom, Lamarck, Anim. sans vert., vol. v. p. G06, ej. 2, vol. vi. p. 370.

Venu>s uudnhjxa, Plulippi, Abbild., vol. i. js. 39, pi. i. tig. 1.

Ventts undnlosa, Sowerby, Thes. Concb., vol. ii. p. 738, pi. 158, fi,L;s. 142-146.

Venus undidosa, Eeeve, Conch. Icon., fig. 126, a, h.

Venus uvdidosa, Pfeiffer, Conch. -Cab., ed. 2, p. 186, pi. xxiii. fig. 3.

Gumyhinu undulosa, Morcb, YolJi Cat., p. 19.

Cliione undulosa, Deshaj'es, Cat. Conchif. Brit. Mus., p. 152.

Chione (Marcia) undulosa, H. and A. Adams, Genera Moll., vol. ii. p. 423.

Venus {Gomphina) undidosa, Eonier, Mai. P.liitt., 1865, vol. xii. p. 143.

Tivula ujididosa, Angas, Proc. Zool. Soc. Lond., 1867, p. 922.

w&x.l^ Cijtherea{Gonvp}iinu) moercld, Angas, Proc. Zool. Soc. Lond., 1872, p. 611, pi. Ixii. fig. 7.

Habitat. — Station 187, near Cape York, North Australia, in 6 fathoms; coral mud.

In the British Museum there are sj^ecimens of this variable yet easily recognisable
species from Swan River collected by Captain Mangles, R.N., and Mr Jukes, and a totally
white variety from Sydney.

The shell described by Angas under the name Cytlierea [Gomphina) moerchi, from an
unknown locality, I believe to be an extreme variation of the present species. The type,
presented to the British Museum by the author, appears to me somewhat distorted at
the posterior end of the ventral margin, which gives rise to the slight sinuation at that
part. The composition of the hinge, the muscular scars, pallial sinus, lunule, and
external sculpture are absolutely identical as in Venus undulosa. The main distinction
is that of form. In typical specimens the umbones are situated somewhat in advance
of the centre, the anterior slope being in consequence shorter than the posterior. In
the example described by Angas they are as nearly as possible central, and the dorsal
margins about equal. The colour of this shell is also rather peculiar, the undulating
zigzag painting being pinkish instead of brown, which is the usual tint when present.
The wavy lines across the lunule and area are precisely similar as in certain undoubted
forms of this species before me. Another indication of its specific identity is the
presence of two somewhat interrupted rays which fall exactly in the positions as in
many normal examples, namely in a divergent manner from the umbones to the ventral
margin. The single Challenger s^secimen has a peculiar coating or pseudo-epidermis of
carbonate of lime of a fibrous nature, the fibres being at right angles to the surface of
the shell.

Cijtherea, Lamarck.

Cytherea [Callista) chione, Linne.

Habitat. — Tenerife, Canary Islands, at a depth of 70 fathoms.

This species is so well known that I refrain from giving any references or synonymy.

KEPORT ON THE LAMELLIBRANCHIATA. 133

It has been recorded from the south uud west coasts of Enghuid, tlie coasts of France and
Portugal, throughout the Mediterranean, and from the Canary Ishmds. It is also found
fossil in the Coralline Crag and in the Tertiary formations of Italy and Sicily.

Cytherea (Callista) rutila, Sowerby.

Cijtherea rutila, Sowerby, Thes. Concb., vol. ii. p. 743, pi. clxiii. fig. 20-5.
Diow rutila, Reeve, Couch. Icon., fig. IS.
. Dione rutila, Deshayes, Cat. Conchif. Brit. Mus., p. 58.

Habitat. — Station 162, off East MonccBur Island, Bass Strait, at a depth of 38 to 40
fathoms ; sand and shells.

The following are the measurements in millimetres of three specimens in the Cumin-
gian collection and the single valve (the smallest) from the above locality.

Length.

Height.

Diameter

18f

13J

In many respects Cytherea rutila resembles Cytherea cliemenensis, and, indeed, at
one time I was inclined to consider them forms of one and the same species, which may
yet be shown to be the case. The former, judging from the three large specimens and a
fourth in the young state in the Cumingian collection, is not so long as the latter
species, smoother, has large blotches on the hinder dorsal slope, and a slightly more
elongate lunule, and appears to attain a larger size. The brown rays are frequently
interrupted or partially concealed by broad and narrow concentric pale zones. Another
distinction is the absence of the purple ray which occurs in Cytherea diemenensis. The
two young odd valves from Station 162, off East Moncoeur Island, and a small specimen
in the Cumingian collection, are rather more elongate than the typical form.

Cytherea I^CaUista) lilaeina, Lamarck.

Cijtherea lilaeina, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 303, No. 15.

Cytherea lilaeina, Hanley, Rec. Shells, p. 98, pi. xv. fig. 12.

Cytherea lilaeina, Sowerby, Thes. Conch., vol. ii. pi. cx.xx. fig. 74.

Dione lilaeina, Reeve, Conch. Icon., vol. xiv. fig. 5.

Cytherea (Callida) lilaeina, Rbmer, Monogr. Venus, vol. i. p. 61, jil. xviii. figs. 2-2t.

Cytherea pectoruli)-, ? Lamarck, loc. eit., p. 304.

Cytherea pectoralis, Sowerby, loc. cit, pi. cxxx. fig. 75.

Dione grata, Deshayes, Cat. Conchif. Brit. Mus., p. 62.

Dione grata. Reeve, loc. eit., fig. 14, a, b.

Cytherea (Callista) grata, Romer, loc. cit., p. 64, pi. xix. fig. 5.

Habitat. — Station 212, south of the Philippine Islands, in 10 to 20 fathoms ; .sand.

1JJ4 THE VOYAGE OF H.M.S. CHALLENGER.

I caimot discover any sufficient reasons for separating Ojtherea Ulacina and Cytherea
ijrata. The difl'erences of form, the thickness of the concentric costse, and the slight
variations in the depth and height of the pallial sinus are so changeable that one scarcely
finds any two specimens alike. Two that correspond as regards the strength of the ribs
may be unlike in respect of the form of the sinus in the pallial impression, and, on the
other hand, I find other examples agreeing in the latter respect but differing in the
former. Cytherea costata, Chemnitz, is also very closely related, and indeed insensibly
passes into this species through the variety fig. lih of the Conchologia Iconica. This is
regarded by Eomer as a form of Chemnitz's species. In my judgment, however, it comes
intermediate, agreeing in the general tone of its colouring with Cytherea grata, l)ut
being rather more strongly ribbed than the typical form of that species. The amount of
violet-red markings around the lunule and on each side of the dorsal area is also subject
to much variation. In Cytherea Ulacina there is either none at all or but very little,
whilst in the type of Cytherea grata there is considerable ; but in the series of specimens
before me I find some which have rather less. The lunule also varies in form and colour,
in some instances being much broader than in others, although the shells may eoi-ncide
in other respects.

Cytherea [Callista) multistriata, Sowerby (PL I. figs. b-be).

Cytherea muUitd7-iata,Sowei:hy,Thea. Conch., vol. ii. p. 628, pi. cxxxvi. fig. 177 (too highly

coloured).
Dioiie multistriata, Deshayes, Cat. Biv. Brit. Mus., p. 64. (var. /J. exclusa).
Callista multistriata, Hutton, Man. N. Zeal. Moll., pp. 149 and 203.
(nee Cytherea multisfriatn, Etimer, Monogr. Venus, sub-gen. Cytherea, p. 72, pL xsi. tig. 1 ;

nee Dione multistriata, Eeeve, Conch. Icon., fig. 60 = Cytherea diemenensis, Hanley).

Habitat. — Station 1G7a, Queen Charlotte Sound, Cook Strait, New Zealand, at a deirtli
of 10 fathoms, mud ; Wellington (Hutton).

No characteristic figure of this species has yet been published. That in the Thes.
Con. is much too highly coloured, and represents a specimen rather unusually high at
the umljones, with the dorsal margin more oblique on both sides than in the majority of
specimens.

The form is oval, rather acuminate posteriorly. It is moderately convex, a little
glossy, finely concentrically striated, the intervening ridges resembling thread-like lirse.
It is very inequilateral, half as long again as high, of a buff colour, variegated with
interrupted rays and irregular wa\^ lines of a pinkish-brown tint, and frequently exhil)its
at intervals two or three bluish concentric zones. The interior is white, with a large
purple patch occupying the central and upper j)ortions of the valves. The lanceolate
lunule is generally light purple, and marked off by an impressed line.

REPORT ON THE LAMELLIBRANCHIATA. 135

Cytherea [Callista) disrupta, Sowerby (PI. I. figs. A-Ae).

Cytherea disrupta, Sowerbj-, Thcs. Conch., vol. ii. p. 74.3, pi. clxiii. figs. 208, 209.

Testa transversim eloHgato-ovalis, postice subacuminata, modice convexa, valde
insequilateralis, nitida, concentrice tenuissime striata, incrementique lineis sulciformibus
et liriformibus oriiata, sub epidennide tcnui, alba roseo-fusco copiose subradiata, irregu-
lariterque maculata, in dorsum postice maculis saturatioribus magnis tres vel quatuor
irregularibus picta. Margo dorsalis posticus elongatus, aliquanto convexus, oblique
descendens, anticus paulo concavus, declivis, multo brevior. Ventris margo incrassatus,
late curvatus, aiitice loiige adscendens. Lunula ovato-lauceolata, coucava, plerumque
alba, linea incisa circumscripta. Umbones mediocres, parum elevati, circiter in \ longi-
tudinis coUocati. Pagina interna alba, umbones versus macula magna livido-purpurea
tincta. Cardo dentibus approximatis. Sinus pallii profundus, latir.sculus, ad apiccm
oblique truneatus, angulo terminali acuto.

Xhe form of this species is transversely long oval, ratlier more acuminate behind
than in front. The dorsal margin is elongate, somewhat arched and oblique posteriorly,
the anterior portion being less than half the length of the posterior side, more sloping
and concave. The lower outline is widely arcuate, and rather more ascending in front
than behind. The shell is moderately convex, very inequilateral, finely concentrically
striated, and exhibits rather coarse lines and grooves of growth, especially in adult shells,
which do not, however, affect the dorsal area. Beneath a very thin epidermis it is
whitish, copiously stained and blotched irregularly with a pinkish-brown colour, generally
in a more or less subradiating manner, and upon the hinder dorsal area, and in front of
the lunide, it is ornamented with a few large darker blotches. The lunule is concave,
generally white, or with perhaps one or two small dark brown specks upon it, of an
ovate-lanceolate form, and enclosed by a fine impressed line. The umbones are small,
a little raised above the hinge-line, rosy at the apices, and situated at a little more than
a quarter of the whole length from the front end. The interior is white at the sides
and lower margins, which are rather thickened, but from the centre to the beaks is
.stained wath a livid purplish tint, which in full-grown specimens is more or less concealed
by callus. The hinge is rather slight and composed of fine approximated teeth. The
sinus in the pallial line is wide and rather deep, but not reaching quite to the centre of
the valves. It is obliquely broadly truncated at the end, the upper angle being
rounded and the lower rather acute.

The dimensions of half-grown specimens are — length 26 mm., height 18, diameter
11|. Adult examples are 41 mm. in length, 32 high, and 21 in diameter.

Habitat. — Port Jackson, New South Wales, in 2 to 10 fathoms.

There are two or three species with which this is likely to be confounded, namely,

liiQ THE VOYAGE OF H.M.S. CHALLENGER.

Cytherea multistriaia, Sowcrby, Cytherea diemenensis, Ilauley, aud young specimeus
of Cytherea viuUiradiata, Sowerby. Cytherea disrupta is a more solid shell than
Cytherea midtistriata, uot (|uite so acute posteriorly, with the valves peculiarly thickened
at the margins, the dorsal area conspicuously blotched, the luuule for the most part white
aud concave in the middle, the dorsal line on this side being excavated in consequence.
On the other hand, in Cytherea midtistriata, the lunule is coloured, not sunken in the
middle, the dorsal outline straight, the posterior area generally more faintly blotched,
and the edge of the valves is acute.

The latter species is also differently striated, the tone of its colour not quite similar,
the hinge even slighter, and tlie beaks not, as a rule, rosy at the tips.

Cytherea diemenensis, 11avl\qj^= Cytherea innocens, Bowevhy = Cytherea multi-
striata, Romer'' and Reeve ^ {non 8owevhy) "^ = Cytherea planatella, Lamarck,* is not so
oval as the species above described, has the anterior dorsal margin straight and much
more descending, and more regular markings, the interior displaying only a single
purplish ray directed posteriorly from the umbones.

, Cytherea (Callista) roseotincta, n. sp. (PL I. figs. 6-6/>).

Testa transversim ovalis, valde incequilateralis, nitida, striis coucentricis tenuissimis,
antice paulo distinctioribus, sculpta, albida, roseo (marginem versus radiatim) irregulariter
tincta, area et lunula maculis paucis parvis notatis. Margo dorsi posticus elongatus,
leviter arcuatus, paulo obliquus, anticus declivior, subrectilinearis. Ventris margo late
regulariterque arcuatus. Umbones parum elevati, incurvati, apicibus rosaceis, in
circiter ^ longitudinis positis. Lunula elongato-cordata, leviter depressa, medio
promiuens, linea elevata circumdata. Cardo mediocriter fortis, dentibus erectis
approximatis. Pagina interna alba, umbones versus pallido-roseo sub-biradiatim suftusa.
Cicatrix autica parva, acute ovalis, postica major, rotundata. Sinus pallii profundus,
latus, ad apicem oblique truncatus.

This species is only moderately convex, transversely oval, a little narrower in front
than behind, very inequilateral, of a whitish colour copiously mottled and stained with
light fleshy pink, which towards the margin is of a darker tint and disposed in rays.
The dorsal area has a few cross-bars of the same colour, and the lunule is also lineated
with it. The valves are glossy and very finely concentrically striated, except at the
anterior side, where the stria3 are rather deeper and coarser. The hinder dorsal margin
is elongate, a little obliquely and slightly curved, the anterior being much shorter, more
descending, and almost straight. The lower outline is gently arcuate, aud ascends a

' Proc Zo:>l. Soc. Land., 184-4, p. Uli. ^ Monogr. Venus, subgenus Cytherea, p. 72, pL xxi. tig. 1.

^ Conch. Icon., fig. 6e, ^ Anim. sans Vert., ed. 2, vol. vi. p. 30.").

)

REPORT ON THE LAMELLIBRANCHIATA. 137

trifle more in front than behind. Tiie beaks are small, a little raised above the hingu-
line, incurved, rosy at the tips, and situated at about a quarter of the whole length
from the anterior extremity. The teeth are small, erect, and much approximated. The
interior is whitish, and exhibits two broad pale rosy red rays towards the upper part.
The anterior muscular impression is oval, acute at both ends, the hinder being larger
and rounder. The pallial sinus is large, broad, deep, extending to the centre of the
valves, obliquely truncated at the end, the upper corner of the truncation being rounded,
and the lower one sharply rectangular.

Length 17^ mm., height 13, diameter 8^.

Habitat. — Station 212, south of the Philippine Islands, at a depth of 10 to 20
fathoms ; sand.

This species probably attains larger dimensions than those given above. It is
distinguishable on account of its fine striation and the peculiar distribution and tone of
its colouring.

Cytherea phasianella, Deshayes, approaches it in form, but is a little broader in front
and ixiore acuminate posteriorly. Cytherea roseotincta is, however, readily distinguished
by its finer strife, difierent painting, slighter hinge, and larger muscular scar at the
hinder end.

Cytherea (Caryatis) rostrata, Koch.

Cytherea rostrata, Koch, Philippi's Abbild., vol. i. p. 150, pi. i. tig. .3.

Cytlwrma rostrata, Sowerby, The.s. Concb., vol. ii. p. 633, pi. cxxxiii. lig. 122.

Diane rostrata. Reeve, Conch. Icon., vol. xiv. fig. 41.

Cytherea (Caryatis) rostrata, Romer, Monog. Venus, vol. i. p. 90, pL xxiv. figs. 3-36.

Venus tehuelcha, d'Orbigny, Yoy. Amer. M^rid., vol. v. p. 5.56.

Habitat. — Station 321, off Monte Video, in 13 fathoms; mud.

M. d'Orbigny was probably in error in stating that Philippi's locality " Brazil " was
not correct for this species. He himself found it at St. Bias on the coast of Patagonia,
and now I record it from Uruguay, so there is every reason to conclude that it ranges
still further north as far as South Brazil. The pallial sinus is at times shorter and
broader than in the specimen figured by Romer, and the form of the shell is higher in
proportion to the length. The following measurements of an extreme example will
illustrate this.

Length 39 mm., height 37^.

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 18

138 THK VOYAGE OF H.M.S. CHALLENGER.

Ct/therea {Can/atifi) hchrcm, Lamarck.

Cijtherea hehneii, Limarck, Anim. sans vert., vol. v. p. .508, ex\. 2, vtjl. vi. p. 30.^.
Ctjthcrea hehrwa, Delesseit, Eecueil de Coq., pi. viii. fig. 6.
Cytherea hebroici, Hanley, Cat. Biv., p. 99, suppl. pi. xiii. fiy. 21.
Dionehehnea, Deshaj'es, Cat. Conchif. Brit. Mus., p. 67.
Cuxe hehntu, Keeve, Conch. Icon., fig. 34.

Venus {Cytherea, sect. Caryatis) hehrcea, Eonier, Monog. Venus, p. 116.
? Venus {Cytherea, sect. Caryatis) soligena, Ebmer, loc. cit., p. 118, pi. xxxii. fig. 1.
Cytherea sophiw, Angas, Proc. Zool. See. Lend., 1877, p. 176, pi. xxvi. fig. 23.

Habitat. — Station 212, Malanipa, Philippine Islands, 10 to 20 fathoms, sand;
Cape Solander, Botany Bay, New South Wales, after a gale (Angas).

This species appears to var}^ rather as regards shape. The typical form, judging
from Delessert's figure, is rather trigonal, acuminately produced at the hinder extremity.
Certain specimens in the British Museum are much broader at this pai't, yet are
evidently the same species. The single valve from the Philippines is remarkably short
and high, being less elongate even than the shell figured by Reeve. The young
example described by Angas under the name Cytherea sojihia? is rather more oblong than
usual, but in other respects agrees precisely with normal specimens of the species. The
small brown stain within the valves at the apex of the umbones is apparently present
in the majority of specimens, and forms a good distinguishing feature. When present,
it is also visible on the exterior, having the appearance of a livid or purplish stain (in
some instances darker than in others), chiefly upon the anterior side of the beaks. The
surface is rather glossy, concentrically finely striated, and exhibits at intervals shallow
grooves which probably indicate periods of growth. The lunule is large, ovate-cordate,
slightly excavated and very feebly elevated along the centre. It is circumscribed by an
incised line, and generally painted with wavy brown markings which do not appear ever
to cross the incised boundary. The dorsal area is not clearly defined, but merely
sunken along the middle, the surface of the valves gradually rounding over to the
margin. The umbones are rather prominent, well incurved, and situated at a point
Avhich does not mark ofi" one-third of the entire length of the shell from the anterior
end. The two cardinal teeth in the right valve, immediately beneath the beak, are
very small and very close together. The corresponding ones in the left valve are very
unec[ual in thickness and united above, the anterior being very slender and lamellar,
whilst the posterior is triangular and stout. The lateral tooth in this valve is
compressed, erect, and stands about a third of the way down the lunule. The anterior
muscular scar is nearly oval, the posterior much broader and rounded. The pallia! line
in the largest specimens has a ragged upper edge, and the sinus is largish, bluntly
triangular, the apex being sharply rounded, but does not reach quite to the centre of
the valves. The colour of this species is white, ornamented witli blotches of an

EEPORT ON THE LAMELLIBRANCHIATA. 139

ochreaceous or brownish-ochre colour, leaving triangular white spots among them.
Sometimes the lower portion of the valves have angular zig-zag lines, displaying a
somewhat irregular transverse arrangement.

This species was not recognised by Romer at the time he wrote his monograph, but
I am inclined to think he may have described it under another name. His Cytherea
soUgena must be very closely allied to, if not identical with, this species. Although no
mention is made of a brown stain within the valves at the umbones, in the copy of
his monograph before me, figure 16 exhibits, in front "of the beaks, a purplish blotch as
seen in Cytherea hebrcea, which is indicative of the mark within. Romer's shell is
very like the specimen figured by Reeve, Ijut a little higher, and has the same character
of markings as the single valve" obtained by the Challenger Expedition. Cytherea
pellucida, Lamarck, approaches very closely to this species, but may be distinguished
by the absence of the internal brown blotch, the presence of a dark stain on the lunule,
the brown wavy lines upon it at times crossing the incised line which suiTounds it, and
a more deeply sinuated pallial line, the sinus extending almost if not quite to the centre
of the valves. The style of markings and colour is very similar, and the hinge, about
the same in composition, is not quite so stout as in Cytherea hebrcea. Care must also
be taken not to confound Cytherea hehrcua with Cytherea varians of Hanley, a species
found on the coast of Brazil. This shell is more acuminate in front, more strongly
striated, has a brown spot upon the otherwise white lunule immediately under the
umbones, a stouter hinge, a different style of painting, and no stain in the interior at
the beaks.

Cytherea (Caryatis) coxeni, Smith (PI. I. figs. 7-7e).

Cytherea {Caryatis) coxeni, Smith, Eeport of the "Alert" Mollusea, p. 95, pi. vii. fi^;s. A-A-.

Testa parva, inajquilateralis, trigono-ovata, utriuque subacuminata, mediocriter con-
vexa, alba, lineis teuuibus paucis punctisque pallide rufis ornata, striis sulcisque concen-
tricis angustissimis exarata. Margo dorsi utriuque valde declivis, postice arcuatus, antice
subrectus, brevior ; margo ventralis late curvatus, ad latus anterius oblique uscendens.
Umbones parvi, modice acuti, albi, aut dUute rufescentes, incurvati. Lunula elongato-
cordata, incrementi lineis striata, vex depressa, in medio paulo elevata, linea impressa
succincta. Ai-ea nulla. Cardo fortis, dente mediano valvas sinistrse crasso, laterali
magno, elevato, parum compresso. Cicatrix antica ovato-pyriforniis, postica rotuudior,
major. Sinus pallii subquatratus, superne oblique truncatus.

This species is longer than high, ovate-subtrigonal, ver}^ inequilateral, moderately
convex, white, marked at intervals with narrow aubpellucid zones, and ornamented with
very fine, somewhat angular lines and dots of a light red or brown colour. This

140 THE VOYAGE OF H.M.S. CHALLENGER.

naintiug is so faint that, at a short distance from the eye, it is scarcely observable.
The valves are moderately strong, and finely, concentrically striate and sulcate. The
umbones are smallish, moderately acute, white or pale reddish, curved over towards
the front, and situated at about one-fourth of the entire length from the extremity.
The lunule is smallish, elongate, heart-shaped, scarcely at all sunken, a little elevated
alono- the central line, circumscribed by an impressed line and striated Ijy the lines
of growth. The dorsal margin descends considerably on both sides of the beaks,
the anterior portion being almost rectilinear, and the posterior much longer, and
I'egularly, gently arched. The lower outline is Ijroadly arcuate, more ascending in
front than behind, forming with the upper margin subequal, sharply rounded, lateral
extremities. The hinge is rather strong for so small a shell, having in the left valve
a stout triangular central tooth and a largish elevated and somewhat compressed
lateral. The front muscular impression is ovate-suljp}'riform, and smaller than the
posterior, which is more rounded. The sinus in the pallial line is moderately deep,
wide, and has a squarish aspect as the end is obliquely truncated, the iimer angle
being acute and almost reaching the centre of the valves.

Length 13 mm., height 10^, diameter 7.

Habitat. — Torres Strait, in 3 to 1 1 fathoms (Challenger) ; Port Molle, Queensland,
at a depth of 14 fathoms {Dr. Coppinger in Brit. Mus.).

Cijtherea minuta, Koch (Philippi's Abbild., vol. i. p. 200, pi. iii. fig. 8), is a more
ecpiilateral species than that under consideration, has a larger lunule, and a narrower
and somewhat deeper pallial sinus.

The specimens from Torres Strait are almost entirely white, with the exception of the
reddish apices of the umbones, but this absence of painting may or may not Ije usual.

Cythereu (Carijatis) regularis, n. sp. (PL I. figs 8-86).

Testa parva, inasquilateralis, parum inflata, alba, sul)tenuis, trigono-rotundata,
conceutrice regulariter ac tenuiter lii-ata, lunula magna, baud profunda instructa.
Umbones promineutes, incurvati, latus anticum versus curvati, concentrice tenuiter
striati, alicpianto ante medium siti. Margo dorsalis posticus elongatus, curvatus,
obliquus ; anticus brevior, minus arcuatus, obliquior ; ventralis late rotundatus. Latus
anticum latins quam posticum. Pallii sinus triangularis, profundus.

This species is a little longer than high, somewhat inequilateral, and inflated,
thinnish, white, subtrigonal, rounded, a little produced and narrower liehind than in
front, sculptured with regular, fine, concentric narrow grooves and intervening rounded
Yivse, very slender at first, and increasing in thickness with the growth of the shell. The
uml)ones are well produced and incurving towards the front and situated decidedly in
advance of the centre. The lunule is large, cordate, not sunken, and is marked off by

REPORT ON THE LAMELLIBRANCHIATA. 141

a conspicuous impressed line. Tlie hinder dorsal slope is .a little arched, oblique, and
longer than the anterior, which is also feebly curved and a trifle more descending. The
front lateral margin is regularly well curved ; the posterior a little more acutely, which
is more marked as tlie shell increases in size. The lower outline is an even Ijroad
curve. Hinge rather similar to that of the European Circe minima, but differs in
having the hindmost tooth in tlie right valve, and the central one in the left thicker
and bifid. The ligamental groove is elongate and narrow. The muscular scars are
large, and the pallial is large, triangular, reaches half across the valves, and terminates
in a rounded tip.

Length 8^ mm., height 7, diameter 5 ; a smaller specimen is 5| long, 5 high, and
4 in diameter.

A larger valve has come to hand since giving the above dimensions. It is 10 mm.
lono- and 9 high.

Habitat. — Torres Strait, North Australia, at a depth of 3 to 1 1 fathoms. Also
Station 188, west of Cape York, North Australia, in 28 fathoms ; mud.

Cijtherea (Dionc) lihiliiypinarum , Hauley.

Cytherea ijhiUppinurnm, Hanley, Rec. Biv. Shells, p. 356, pi. xv. fig. 36.

Cytherea pliilippinarum, Reeve, Conch. Icon., vol. xiv. fig. 4:7, a, h.

Cythenea philippiiiarum, Sowerby, Thes. Conch., vol. iL p. 627, pi. cxxxvi. fig. 177.

Merefrix philippinarum, Deshayes, Cat. Conchif. Brit. Mus., p. 39.

Cyfliereu (Dione) j'hilippinarum, Rijmer, Monog. Venus, vol. i. p. 139, pi. xxxvii. figs. 2-2e

(very exceUeut).
Cytherea inemlana, Philippi, Zeitschr. f. Malak., vol. viii., 1851, p. 72.

Habitat. — Levuka, Fiji Islands, at a depth of 12 fathoms; and in Tahiti Harbour in
20 fathoms ; also at the Banda Islands, in shallow water.

The only localities from which this pretty species appears to have been hitherto
recorded are the Philippine and Marquesas Islands, the former on the authority of Mr.
Cuming and the latter on that of Philippi.

Circe, Schumacher.

Circe .icrijJta (Linne).

Venus scrip)fa, Linno, Syst. Nat., cd. 12, p. 1135.

Circe script a, Sowerby, Thes. Conch., vol. ii. pi. csxxis. figs. 38-42.

Circe scripfa, Reeve, Conch. Icon., fig. 1.

Vcntig (Circe) gcri2jfa, Ro'mer, Monog. VeneriJse, vol. i. p. 193, pi. lii. fig. 1.

Habitat. — Port Jackson, New South Wales, in 4 to 18 fathoms; and Torres Strait,
at a depth of .3 to 11 fathom?.

142 THE VOYAGE OF H.M.S. CHALLENGEE.

The painting of this species, although very variable, is constant in the specimens
from the above localities in two particulars, namely, in being of a dark brown tint upon
the lunule and area, and for the most part uniformly pale upon the flattened umbones.
In the young state the shell is remarkably compressed, a specimen 16 mm. in length
having a diameter of only 2^. This species ranges from the Red Sea through the Indian
Ocean as far as the Moluccas.

Cii'ce sulcata, Gray.

Circe sulcata. Gray, Analyst, vol. viii. p. 307.

Circe sulcata, Romer, Monog. Venus, vol. i. p. 210, pi. Ivii. figs. '2-'2f/.

Circe sulcata, Reeve, Concli. Icon., fig. 16, a~c.

Circe artemis, Deshayes, Cat. Conchif. Brit. Mus., p. 86.

Circe artemis. Reeve, Conch. Icon., fig. 1-5.

Cii-ce metcalfei, Deshayes, Proc. Zool. Soc. Lend., 1853, p. 28.

Cytherea erijthraea, Jonas, Philippi's Abbild., vol. iii. p. 71, pi. ix. fig. 2.

Circe pacta, Romer, Mai. Blatt., 1860, vol. vii. p. 155.

Cytherea pleheia, Hanley, Rec. Biv. Shells, p. 356, pi. xv. fig. 37.

Habitat. — Station 212, south of the Philippines, in 10 to 20 fathoms, on a sandy
bottom ; also off Levuka, Fiji Islands, in 12 fathoms.

Circe metcalfei, Deshayes, is identical with Circe artemis of the same author, and
not a variety of Circe undatina as suggested by Romer. It is rather more coarsely
concentrically ridged than the typical form of this species, bluish-white, varied with
very little of the brown painting which usually adorns this species. The specimens from
the first locality are half-grown examples of the variety pleheia.

Circe atistralis, Sowerby.

Circe mcstralis, Sowerby, Thes. Conch., vol. ii. p. 651, pi. cxx.xvii. tigs. 16, 17.

Circe australis, Deshayes, Cat. Brit. ]\Ius., p. 87.

Circe australis, Reeve, Conch. Icon., fig. 19.

Ventis (Cytherea {Crista)) australis, Riimer, Monog. Venus, vol. i. p. 186.

Habitat. — Station 188, south of New Guinea, at a depth of 28 fathoms ; green mud.

This species is rather more compressed than Circe dispar, more finely concentric-
ally ridged, and has very much finer diverging sculpture at the sides. There are
specimens in the British Museum from Friday Island, Torres Strait, and North-east
Australia.

EEPORT ON THE'LAMELLTBRANCHIATA. 143

Circe gibbia (Lamarck).

Ci/fherea gihbia, Lamarck, Anim. sans vert., vol. v. p. 577.

Cytherea gibbia, Sowerby, Gen. of Shells, fig. 3.

Circe gibbia, Sowerby, Thes. Conch., pL cxxxvii. figs. 4-7.

Circe gibhia, Reeve, Conch. Icon., fig. 21, a-d.

Venus (Ci/tJierea (Crista)) gibbia, Romer, Mai. Blatt., 1863, p. 17.

Venus (Cytherea (Crista)) gibbia, Romer, Monog. Veneridffi, vol. i. p. 176, pi. xIviL fig. 2.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

This species has been recorded from several localities in the Indian Ocean, from the
Philippine Islands, and from New Caledonia.

Cii'ce bermudensis, n. sp. (PI. II. figs. 1-1 6).

Testa parva, trigono-rotundata, paulo insequilateralis, albida (?), mediocriter convexa,
utrinque rotundata, Uiis radiantibus et concentrieis tenuibus cancellata. Margo dorsi
utrinque valde declivis, postice leviter arcuatus, antice rectiusculus, ventralis parum
curvatus. Umbones mediocres, aliquanto ante medium siti, acuti, incurvati. Lunula
impressa, late lanceolata. Dentes cardinales normales, postico valvse dextr^ et mediano
sinistrse maximis. Sinus pallii indistinctus.

This species is longer than high, and becomes proportionately longer as it increases.
It is a little inequilateral, the anterior end, as is usually the case in the Veneridae, being
shoi'ter than the posterior. It is beautifully ornamented with fine concentric lirse, which
are crossed by others equally slender radiating from the apices, the points of intersection
being somewhat granular. It is probably whitish, but I am unable to speak with
certainty upon this jaoint, as all the valves before me are more or less worn. It is rather
rounded when very young, but becomes more trigonal in older shells, the umbones being
more elevated, and thus producing this appearance. The dorsal margin descends con-
siderably on both sides, is rather longer and a trifle arcuate behind, in front being
nearly rectilinear. The two ends are subequal, the posterior, if anything, rather
narrower than the anterior, the reverse being the case in the earlier stages of growth.
The ventral margin ascends more in front than behind, and is not very much curved at
the middle. The lunule is broadly lanceolate, faintly sunken, defined, and exhibits lines
of growth. The hinge is normal in construction, the hinder tooth in the right valve
and the central one in the left beine' rather laro;er than the others. The muscular
impressions and the pallial line are too distinct for description.

Length 7 mm., height 6|, diameter 4^.

Habitat. — Station 33, off Bermuda, at a depth of 435 fathoms ; coral mud.

144 THE VOYAGE OF H.M.S. CHALLENGER.

Tlie cancellated surface, a feature rather uncommon in this genus, will readily
distinguish this from other Atlantic forms. Although the above may not be the full
dimensions reached by the species, I am of opinion that it does not attain a very much
larger size.

Circe jucimda, n. sj). (PI. II. figs. 3-3?*).

Testa rotundata, paulo iuajquilateralis, latere antico postico angustiori, albida,
increment! lineis tenuibus, marginem inferiorem versus aliquanto, fortioribus, sculpta,
costellis numerosis gracilibus radiantibus granulosis utrinque ornata. Umbones parvi,
acuti, incurvati. Margo dorsalis antice vix convexus, leviter obliquus, j^ostice minus
descendens, rectiusculus, vel levissime convexus. Ventris margo arcuatus, antice
sensim adscendens. Lunula mediocriter magna, linea gracillima impressa circumdata,
baud ratiatim lirata. Dentes normales ut in Circe castrense. Margo dorsi posticus
valvse dextrse conspicue intus sulcatus, sulco elongate, profundo.

The valves here described are possibly only the young stage of the species, but the
character of the sculpture is sufficiently peculiar that the adult form would be
recognisable without much difficulty. It is a roundish species, a little longer than
high, slightly inequilateral, the anterior side as usual being the shorter. It is white,
somewhat convex, sculptured with fine striae or lines of growth, which become rather
coarser as the shell enlarges. In addition there are, on each side, numerous very
slender radiating lirae which are a trifle arcuate, especially those upon the anterior end,
and, being crossed b)^ the concentric striae, become finely and very prettily granular.
The umbones are rather small, acute, curve over towards the anterior end, and are but
little elevated above the dorsal line. This is slightly convex, and rather oblique
in front, and forms with the slowly ascending basal margin, which is l>roadly curved, a
narrower, more acutely rounded end than at the opposite extremity. The hinder slope
is less oblique and nearly rectilinear at first, then rounding into the lateral outline.
The lunule is moderately large, scarcely sunken, enclosed by a very fine impressed line,
prominent along the middle, broadly lanceolate in form, and sculptured onl)^ with
the fine lines of increment. The hinge is composed like that of other species of Circe.
In the left valve the central tooth is thick, trianoular, and much stouter than
either of the two others. In the right valve it is also triangular and thickish, but not
much stouter than the posterior, which is rather longer. The hinder dorsal slope in
the latter valve is conspicuously grooved within, the groove being elongate and extend-
ing nearly to the extremity. In the left valve there is a corresponding elevated ridge
between the extreme outer edge of the slope and the inner margin of the hinge-plate.
The ligament would be internal, or scarcely visible from the exterior. The anterior

REPORT ON THE I.AMELLIBRANCHIATA. 145

Tiiuseular impression is elongate and a little smaller than the posterior. The pallial
sinus has not been recoornised.

Length 3 mm., height 2|, diameter 1^.

Habitat. — Station 188, west of Cape York, North Australia, in 28 fathoms, green
mud ; and off the reefs at Honolulu, Sandwich Islands, in 40 fathoms.

Since writing the above description, based ujinn two valves from Station 188, three
more valves from Honolulu have been forwarded to me which agree in every particular.
They are rather largi^r than the figured valve, being 3 J mm. long and 31- high. The
radiating granular ridges, which in the Cape York specimen extend only a short distance
from the sides, are produced almost to a central line down the middle of the valves,
where they divaricate. From the general aspect of those specimens 1 am rather inclined
to think that the species will ])rove permanently small, and possibly not much larger
than the above dimensions indicate.

Circe arnica, n. sp. (PI. TT. figs. 2 -2e).

Testa transversa, ovata- superne acuminata, paululum insequilatcralis, alba, ad mar-
ginem dorsalem utrinque rubro maculata, concentrice subcostata et sulcata, umbones
versus Isevigata, in sulcis et ad utraque latera radiatim lirata. Margo dorsi utriuque
subfequaliter dcclivis, postice levissime arcuatus, autice aliquanto concavus. Ventris
margo late curvatus, acute rotundatim in dorsalem anticam ambiens, cum postico obtuse
angulatim junctus. Umbones parvi, acuti, paulo ante medium collocati. Lunula
lanceolata, linea incisa circumdata, rubro tincta. Area angusta, subju-ofunda, marginilnis
subangulatis, postice rubro maculata. Dens medianus in utraque valva maguus, conicus,
anticus valvse dextrse eodem minor in valva sinistra. Cicatrices subprofundse, antica
parva, elongata, infra dentes laterales sita, postica latior. Sinus pallii medioeriter
latus, sed minime profundus.

The shell of this species is a little inequilateral, the anterior side being rather
shorter than the j^osterior. It is entirely white, with the exception of a spcar-head-
shaped red spot on the front part of the lunule and a smaller spot of the same colour
on the hinder part of tiic posterior dorsal margin. It is considerably longer than high,
about equally broad at each end, rather finely radiately Urate down both sides, and
concentricallv ridged and grooved near the ventral margin, at the beaks and for a short
distance beneath them being almost smooth. The ridges are unequal in size, very little
elevated, and somewhat granulous at the sides, where they are crossed by the radiating
costellfe. The furrows too are shallow and unequal in width, and have a punctate
appearance which is caused by the presence of fine radiating lirse interrupted by the
concentric ridges. The dorsal margin descends about equally on each side, but whilst

(ZOOL. CHALL. EXP. — PART .X.KXV. — 1885.) Mill 19

146 THE VOYAGE OF H.M.S. CHALLENGER.

posteriorly it is tlie slightest excurved, in I'rout it is a trifle concave. The lower out-
line is broadly arcuate, and forms in front with the dorsal margin a rather sharply
rounded extremity, and posteriorly joins the upper margin in an indistinct rounded
angle. The umbones are small, acute, very little elevated, and placed a little in front
of the centre. The central cardinal tooth in each valve is triangular and large, the
anterior in the right is smaller than that of the left, the posterior in the latter is more
slender than the corresponding tooth in the former, and the lateral tooth in the left
valve is conical, elongate, and compressed. The muscular scars are rather deep and high
up, the anterior, which is elongate, commencing immediately beneath the lateral tooth.
The posterior scar is broader, and the pallial sinuation is moderately wide but very
shallow. The margin of the valves is flattened within, except along the hinder dorsal
slope and the lunule, where it is linearly grooved. The lunule is lanceolate, circum-
scribed by a distinct impressed line, not affected by the radiating sculpture, but merely
sti'iated by fine lines of growth, as is also the case with the narrow posterior area,
which is limited by roundly keeled margins. The ligament is small and subinternal.

Length 8f mm., height 7^, diameter 4.

Habitat. — Station 172, off Nukalofa, Tongatabu, in 18 fathoms; coral mud.

Circe fastigiata (Sower by).

Cytherea fastigiafa, Sowerby, Tliesaurus, vol. ii. p. 643, pi. cxxxv. figs. 158, 159.
Circe fastigiata, Eeeve, Conch. Icon., vol. xiv. fig. 11.

Habitat. — Cape York, North Australia, in 3 to 12 fathoms.

A single small valve only was obtained at this locality. It agrees with Circe
fastigiata of Sowerby, which in my judgment is probably only a peculiarly painted
variety of the well-known Circe incta of Lamarck, and I am of opinion that when our
series of specimens from numerous localities has become considerably larger than at
])resent, there will be great difliculty in separating these two forms, in addition to Circe
tigrina, Lamarck, Circe trimaculata, Lamarck, Circe sidcatina, Lamarck, and
Circe hieroglypMca, Conrad.

The shell depicted by Romer (Monog. Venus, vol. i. pi. xlv. figs. 1-lc) as Circe
fastigiata is not Sowerby's species, but rather a foim of Circe tigrina.

Circe gordoni, n. sp. (PI. II. figs. 5-5e).

Testa subtrigona, valde ina^quilateralis, nitida, antice brevis, rotundata, postice
angustata, producta, subrostrata, mediocriter inflata, omnino alba, vel lineis rufis
Iransversis angulato-undulatis picta, liris concentricis, umbones lateraque versus perspicuis,

REPORT ON THE LAMELLIBRANCHIATA.

147

in medio valvarum subobsoletis instructa ; margo dorsi anticus brevis, obliquus, vix
arcuatus, posticus lougior, superne aliquaiito curvatTis, longe dcsoondcns. Margo vcntris
late arcuatus, postice indistiucte subsinuatus. Umboues promincntes, bene incurvati,
apice rufescentc. Lunula parva, late cordiformis, linea elevata rufo picta circumscripta.
Dentes fere ut in Circe picta. Pagina intern;i jihis minusvc fuseo tincta. Cicatrices
parvse, antica elongata, subovata, postica rotuudata. Sinus palHi l)i'evis. minime
profundus.

This species is moderately intiated, very inequilateral, entirely white or ornamented
with a few transverse zig-zag brown lines. It is somewhat trigonal in form, much
broader in front than behind, where it is somewhat rostrate. The surface is glossy,
regularly concentrically finely sulcate upon the beaks, and more coarsely at the sides,
the grooves upon the central portion of the valves becoming more or less obsolete. The
ridges are broader than the sulci which separate them, and rounded, especially those
upon the beaks, which gradually increase in thickness from the apex. The umbones are
considerably elevated, well curved over towards the anterior end, and terminate in a
brown or reddish apex. The dorsal line is straightish in froiit, ohlique, a little arched at
first behind the umbones, then more rectilinear, prolonged, and much descending. The
lower margin is broadly curved, indistinctly subsinuated towards the posterior end,
more arcuate and upcurving in front. The lunule is small, broadly cordate, and enclosed
with a fine elevated line which is bordered on the outside with a few short, reddish
lines. The hinge is very similar to that of Circe picta. The interior is sometimes
almost entirely white, l)ut in other specimens is more or less stained with brown.
When present this colour occui's chieflv aliout the middle of the valves below the
umbones or down the posterior side, biit never in front, judging from the four specimens
under examination. The muscular impressions are small, the anterior one being-
elongate and oval, and the hinder one broader and subpyrifdini. The sinus in the
pallial line is small and very shallow.

Length 15^ mm., height 13f, diameter 10.

Habitat. — Off Levuka, Fiji, in shallow water, and 12 fathoms.

On comparing young specimens of Circe picta, and one or two allied forms, it will
be found that they are very different in form from tlie present species. They are
much more regularly oval, and about as broad liehind as in front, whilst in Circe
gordoni the posterior end is conspicuously narrowed. The umboues too in the latter
are more elevated, the concentric sculpture upon them decidedly stronger, and the
lunule is much shorter and broader. In Circe picta it is generally stained with blackisli-
brown in front of the beaks, Imt in the .species under consideration it is probably
always white.

148 THE voya(;e of h.m.s. challenger.

Circe minima (Montagu).

Vemis minima, Montagu, Test. Brit.j p. 121, jil. iii. fig. 3.

Circe minima, Forbes ami Hanley, Brit. Moll., vol. i. p. 446, pi. xxvi. figs. 4, .5, 6, 8, and PI. JL

fig. 3.
Circe minima, Jefifi'eys, Brit. Cuucli., vol. ii. p. 322, vol. v. ji. 183, pi. .\xxvii. fig. G.
Circe minima, Romer, Monog. Venus, vol. i. p. 214, pi. Iviii. tig. 4.

Habitat. — Tenerife, Canary Lslands, 70 fathoms ; also Station 75, off Fayal, Azores,
in 450 fathoms.

To give, the complete synonymy and references for this species would probably occupy
a whole jJage or more. It is sufHcient to say that I concur in the view taken by Jeffreys,
Hanley, and others, that the Mediterranean form, Circe cyrilli, should not be held sjaeci-
fically distinct. The species is variable in form and sculpture, as demonstrated by any
considerable series from any one locality.

Circe angasi,^ n. sp. (PI. II. figs. i-ie).

Gouldia austrah's, Augas, Proc. Zool. Soc. Lond., 1865, p. 459 ; 1867, p. 928.
Circe australis, Smith, Proc. Zool. Soc. Lond., 1881, p. 491.

Habitat. — Port Jackson, New South Wales, at a depth of 2 to 10 fathoms.

This species is apparently always small, rather trigonal, convex, inequilateral, thin,
glossy, of a pinkish-red tint, whitish towards the utu bones, which are tipped with a deejier
red, also ornamented wdth concentric white lines and narrow zones, and frequently exhibit-
ing two pale rays, more distinctly seen within the shell, one towards each end of the
valves. The luuule and the upper part of the dorsal area arc also stained with the
same deep colour as the beaks. The sculptui'e consists of moderately coarse lines of
growth, the strife towards the anterior end being deeper, and the intervening sublirae
coarser than at the opposite extremity. The umbones are prominent, moderately acute,
a little incurved, and placed well forward at about one-fourth of the length from the
extremity. The hinder end is more prolonged than the anterior and more sharply
rounded. The ventral margin is broadly arcuate, the posterior dorsal oblique, straightish,
the anterior being a little concave and suddenly descending. The lunule is elongate
heart-shaped, very slightly depressed, and clearl)^ defined. Of the three cardinal teeth in
the right valve, the front one is lameUar, the central stouter, somewhat triangular, and
the hinder one large, elongate, oblique, and bifid. In the left valve the latter is elongate
and very slender, the middle one stout, broadest at the Ijasc, and joined above to the
front tooth, which is onl}- half as thick and divergent. The lateral tooth in this valve is
conspicuously large and very near to the cardinal. The pallia! line is remarkably
remote from the ventral margin, with hardly an)^ indication of a jiostcrior sinus.

Length 6 mm., height 5, diameter 3^.

' The name australis having been already used may be changed to aiujasi as above.

IIEPORT ON THE LAMELLIBEANCHIATA. 149

Circe ohliquissiina, n. sp. (I'l. 11. figs. (j-G/v).

Testa parva, valdo oljliqua, sul)pyi-iformi.s, inajqiiilateralis, antice producta, subluuu-
lata, crassiuscula, albida, subdiapliaua, conceiitricu fortitcr costata et sulcata. Umbones
promineutes, subacuti. Cardo crassus. Deutes iii valva dextra tres ; duo postici sub-
aequales, anticus subobsoletus. Sulcus lateralis anticus latus, profundus. Ligamentum
internum, elongatum, pone dentem postremum situm.

Tliis shell is remarkably ol)lique, very inequilateral, the anterior cud being much
greater than the posterior. It is produced in front, pyriforra, very strongly concentrically
grooved and ridged, the ridges being continued to the margins. In front; they are not
interrupted by a decided groove, but merely crossed by a slight depression marking off an
ill-defined lunule. The sulci are unequal, every alternate or third one being deeper and
l)r()ader than those intervening. The colour is white, the texture subdiaphanous, and the
surface somewhat glossy. The beaks are rather prominent, moderately acute, and
directed somewhat towards the front. The hinge is strong for so small a shell, and
consists of three cardinal teeth in the rioht valve. Of these the central is the largest
and parallel witli the hinder one, which forms the inner boundary of the ligamental pit.
The front tooth in the single valve under examination is subobsolete, and forms as it were
the upper extremity of the inner raised edge of the lateral dental groove. The ligament
is oblique, parallel with and located within the posterior dorsal margin. The interior is
glossy, and, owing to the transparency of the shell, exhibits the concentric sculpture of
the exterior. The muscular scars and impression of the mantle are too indistinct for
description.

Length 4 mm., height 3|-, diameter about 2.

Habitat. — Station 186, off AVednesday Island, North Australia, at a depth of 8
fathoms ; coral sand.

This remarkable little shell is peculiar on account of the obliquity of its growth, and
the strong character of the concentric sculpture. It is quite unlike any other species of
the genus.

Subfamily DosiNiix.^.
Dosinia, Scopoli.
Dosinia deshayesii, A. Adams (PL I. figs. 1-le).

Dosinia deshayesii, A. Adams, Proc. Zool. Soc. Lond., 1855, p. 223.
Dosinia deshayesii, Rdmer, Monog. Dosinia, p. 55.

Habitat. — Station 187, near Cape York, North Australia, at a depth of 6 fathoms
(Challenger) ; North Australia (Mus. Cuming) ; Prince of Wales Channel, Torres Strait,
in 5 to 7 fathoms (Dr. Coppinger of H.^M.S. " Alert ").

150 THE VOYAGE OF H.M.S. CHALLENGER.

This species is rather raore ventricose than Dosinia scalaris of Menke, in this respect
asreeinsr better with Dosinia juvenis, Chemnitz. The concentric rido-es are thickened,
with acute edges, upon the central portion of the valves, and separated by deeper
sulci than in the two above mentioned species. At the sides, as in this form,
they are lamellar and more erect. The broad streak in the interior of the valves,
radiating from behind the umbones. is not purple, but dark olive-brown, and is not
present in all examples. In some specimens of Dosinia juvenis a similar style of paint-
ing is met with.

With regard to form, this species approaches nearer to Dosinia scalaris than Dosinia
juvenis, which is higher in proportion to the length, and does not, so far as I am aware,
attain such large dimensions as Dosinia deshayesii, w^hich are as follows : — length 50 mm.,
height 45, diameter 26. The area is deeper than in Dosinia scalaris, and defined by
angular edges, particularly noticeable in the left valve, resembling Dosinia juvenis. On
the contrary, the pallial line is nearer the margin in this species and Dosinia scalaris
than in Dosinia juvenis.

Adams describes the colour as "rufescente, albo variegata." This description does
not give a sufficient idea of the painting of this shell, which may be said to be reddish-
brown varied with four more or less distinct white rays, one down the posterior dorsal
slope, one bordering the lunular margin, and the two others upon the centre of the
valves. These rays in some specimens are almost obliterated or confused with the
ground colour of the shell, and at the two ends of the valves there are frequently more or
less angular markings and oblique lines upon the pale rays. The lunule is ^particularly
wide, certainly wider than in Dosinia scalaris, if not deeper. In conclusion, I may
observe that all these three species are very closely related, and by some might be
regarded as variations of one and the same species, but if Dosinia .scalaris be
retained distinct from Dosinia juvenis, we must then admit the validity of the
present form.

Dosinia circinaria, Deshayes (PI. I. figs. 2-2f ).

Dosinia circinaria, Deshayes, Cat. Conchif. Brit.. j\Ius., p. 9.
Dosinia circinaria, Romer, Monog. Dosinia, p. 19.

Habitat. — Port Jackson, New South Wales, in 6 to 7 fathoms.

The localit)- of this species has not hitherto been known. The tip of the umbones
appears to be generally stained with a pale brownish colour, a feature not referred to by
Deshayes, who also does not give any dimensions. The type which is now figured is
28 mm. long, 27 high, and 16 in diameter.

REPOllT ON THE LAJlELLIBltANCHlATA. 151

Dosinia lamhata (Gould).

Arthemis lamhata, Goiiltl, Wilkes' Explor. Exped., vol. xii. p. 422, figs. 536-536a; Otia

Conchol., p. 84.
Artemis lamhata, Hutton, Manual X. Zeal. Moll., p. 1,50.

Testa subcircularis, superue producta, mediocriter teuui.s, nitida, alba vt-l lutesceiis,
insequilateralis, tenuissime concentrice striata, interstitiis ad latera quam in medio magis
elevatis, radiatim microscopice striata. Lunula parva, depressa, in medio paulo
prominens, acute cordata. Area postica inconspicua, angusta, baud profunda, marginibus
rotundatis limitata. Umbones prominentes, aliquanto incurvati, circiter in f longitudinis
locati. JNIargo dorsi anticus valde descendens, excavatus, lunula indentatus, posticus
minus descendens, leviter arcuatus. Cardo mediocriter levis, dente postico valvse dextrse
elongato, gracili, ad apicem fisso. Sinus pallii elongatus, adscendens, vix ultra medium
valvarum productus, ad apicem obtusus.

This species is as high as long, rather circular, produced above at the l)eak.s, moderately
convex, inequilateral, glossy, dirty white, creamy white or pale yellowish-brown, marked
with excessively tine concentric striae, near the umbones scarcely visible to the naked eye,
all of which do not reach the dorsal margin, so that the interstices at the sides (especially
posteriorly) are broader, more elevated, and conspicuous than those on the central portion
of the valves. These are rather thin, and sculptured by numerous faintly impressed
radiating lines or substrise and also by countless other strite which cannot be seen except
with the aid of a microscope. The vimbones are somewhat produced, acute, curved over
a little at the apex and located far towards the anterior end. The ventral outline is
semicircularly arcuate, joins the hinder dorsal slope in a very faint rounded angle, and
runs into the anterior or lunular margin in a sharpish curve. The posterior dorsal
margin is a little convex, somewhat oblique, and much longer than the anterior side, which
descends rather abruptly and is concave, indented or irregular on account of the lunule.
The hinge-plate is not very thick, having the posterior tooth in the right valve elongate,
thin and grooved at the top, the central one in the left in young shells deeply cleft, and
the anterior lateral tooth very small, or almost obsolete. The anterior scar is long and
narrow, the posterior rather broader. The pallial sinus is deep, narrowly triangular, sub-
acute at the apex and produced upwards a little beyond the centre of the valves. The
ligament is visible externally, but a little sunken below the dorsal line. The lunule is
very small, elongate heart-shaped, sunken at the sides, and elevated along the central
line.

Length 37 mm., height 3G, diameter 20.

Habitat. — Station 167a, Queen Charlotte Sound, Cook Strait, New Zealand, in 10
fathoms, mud. " North Island only" (Hutton).

This species is remarkaljle for the excessive fineness of the concentric sculpture and

152 THE VOYAGE OF H.M.S. CHALLENGER.

the two kiucls of radiating strias, tliu one visiljle in certain positions to the naked ej'e, tlie
other microscopic. I know of but one or two other species so finely sculptured.

Dosinia anus, Philippi, and Dosinia suhrosea, Gray, both likewise from New Zealand,
are more strongly Urate, the former being the most coarsely scul]iturod of all. In Dosinia
anus the pallial sinus points below or at the lower end of the anterior scar, in Dosinia
suhrosea at the middle of the scar, and in Dosinia lamhata it is directed still more
upward. The great difference in the sculpture at once distinguishes Philippi's species
from the present, and Dosinia suhrosea, besides being rather more strongly lirate, is
different in form. It is a broader shell witli the beaks less prominent above, and has a
more distinct posterior dorsal angle. All three species have a microscopic radiating
sculpture, l)ut that oi Dosinia lamhata is the finest.

Dosinia hist rid (Gmelin), var.

Dosinia histvio (Gmeliu), Eomor, Jlonog. Dosinia, p. 33, pi. vi. figs. 2, 3.

Habitat. — Station 187, near Cape York, in 6 fathoms; also Flinders Passage, in 7
fathoms ; and at Station 189, Arafura Sea, in 25 to 29 fathoms.

The specimens from the first of the above localities are entirely white, and very closely
and delicately concentrically lirate. They are perhaps a trifle higher in proportion to the
length than is usual. The following are the measurements of two specimens.

Length 33^ mm., height 33-i^, diameter 19.

Length 30 mm., height 30, diameter 18.

This species has received several names from various authors. It is the J^entis
australis of Quoy and Gaimard, the Artemis variegata of Reeve, Artemis Virata and
lenticularis of Sowerby, and jjerhaps the Artemis scabra of Philippi.

The specimens from Station 187 and Flinders Passage resemble the variety Artemis
lirata.

Dosinia mira, n. .sp. (PI. I. figs. 3-3t').

Testa alba, cretacea, tenuis, parum insequilateralis, trausversim rotunde ovata, medio-
criter convexa, concentrice dense lirata et lamellata, lamellis tenuissimis, angustis,
irregulariter plus minusve interruptis vel abruptis, interstitiis radiatim substriatis.
Lunula cordata, modice profunda, in medio prominens, tenuiter lamellato-lirata. L^m-
bones valde incurvati, mediocriter prominentes, paulo ante medium siti, apicibis nitidis,
striatis. Margo dorsi anterior valde obliquus, vi.x curvatus, posticus rectiuseulus, minus
descendens. Ventris margo late regulariter(|ue rotundatus. Area dorsalis inconspicua,
angusta, hand excavata, in medio prominens, utrinque sulco baud })rofundo, inconspicuo

REPORT ON THE LAMELLIBRANCHIATA. 153

marginata. CarJo Icvis, aiigustus, dentibus tcnuil)us raunitus. Ligamentum angustum,
clongatum, couditum, omniuo internum. Pallii siuus angularis, apice truncato, usque ad
medium valvje prolongatus. Cicatrix antica elougata, angusta, postica paulo latior,
superne lobata.

The shell of this pretty species is rather thin, longer than high, transversely roundish
ovate and a little inequilateral, the anterior side being the shorter. It is dull chalky
white, very finely and closely concentrically lirate, and lamellated and radiately sculptured
in the interstices with minute and very close substrife. The lamellse are excessively thin,
fragile, not much elevated, and more or less broken in many places, giving the surface a
very ornamental appearance. Upon the most convex portion of the valves, and towards
the urabones, they are for the most part worn down, and there take the form of fine lira3.
The lunule is moderately deeply sunken, cordiform, with straightish sides, elevated along
the middle, and sculptured with fine lamellas of growth. The posterior area is not very
apparent, narrow, raised along the dorsal margin and defined by an indistinct shallow
depression on each side. The umbones are moderately elevated above the hinge-plate,
well curved over towards the front, glossy and finely concentrically striated at the apex.
The outline of the valves is regularly curved all round except upon the dorsal margins,
which are somewhat straight, the anterior being rather more oblique than the posterior.
The ligament is altogether internal, narrow, and long. All the teeth are slender, the
central one in the left valve being remarkable in this respect and widely divergent fi-om
the thin, erect, anterior tooth. The pallial sinus is deep, extending obliquely upwards a
little beyond the middle of the valve ; its sides are straight, converging, and the apex is
truncated. The front muscular scar is long and narrow, the posterior a little broader,
having a little lobe at the upper end.

Length 33 mm., height 28^, diameter 17.

Habitat. — Station 189, south-west of New Guinea, in 25 fathoms ; green mud.

Dosinia sculpta (Hanley).

Artemis sculpta, Hanley, Cat. Eec. Biv. Shells, Append., p. 357, pi. xv. fig. 42
Artemis sculpta, Sowerb}% Tlies. ConcL, vol. ii. p. 659, pi. cxli. fig. 15.
Artemis scul2^ta. Reeve, Conch. Icon., vol. vi. fig. 52.
Dosinia sculpta, Eomer, Monog. Dosinia, p. 38.

Habitat. — Torres Strait, in 3 to 11 fathoms.

Only a left valve of a young specimen was collected at the above place. At this
age the apex of the umbones is tinted with pale rose, which generally appears to fade
away as the shell arrives at maturity. There are specimens in the British Museum said
to have been obtained at Moreton Bay, Queensland, by Mr. Strange.

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 20

154 THE VOYAGE OF H.M.S. CHALLENGER.

dementia. Gray.
dementia papyracea (Gray).

Vi-mis {?) 2)a]:>ijracca, Gray, Ann. Philosoph., 1825, vol. ix. p. 137.

Verms papyracea. Wood, Index Test. Suppl., p. 5, pi. ii. fig. 8.

Clcmentia (gen.) Graj', Synopsis Contents Brit. Mus., 1840, p. 149, and 1841, p. 127.

Clemeiitia papyracea, Gray, Proc. Zool. Soc. Lond., 1847, p. 184.

dementia papyracea, Sowerby, Thes. Conch., vol. ii. p. 700, pi. cli. fig. 155.

Glementia paprjracea, H. and A. Adams, Genera Eec. Moll., vol. ii. p. 433, vol. iii. pi. cis. fig. 1.

Clementia papyracea, Chenu, Manuel de Conch., vol. ii. fig. 410.

dementia papyracea, Pfeiffer, Monog. Veneridaj, in Conch. -Cab., ed. 2, p. 254, pi. xxxi. fig. 16.

dementia papyracea, Kobelt, lUust. Conchy 1., pi. xcvii. fig. 14.

Artemis {dementia) papyracea, "Woodward, Man. Moll., p. 306.

Veims hyalina, Philippi, Abbild. und Beschr., Bd. iii. p. 83, pi. x. fig. 6.

dementia hyalina, Pfeiffer, loc. eit. supra, p. 253, pi. xxxi. figs. 9-13.

dementia cumingii, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 346.

dementia moretoniensis, Deshayes, loc. cit., 1853, p. 18.

Clementia strangei, Deshayes, loc. cit., 1853, p. 17.

dementia subquadrata, A. Adams, MS. in Mus. Cuming.

Var. juv. = dementia similis, Sowerby, Thes. Conob., vol. ii. p. 700, pi. cli. fig. 156.

Habitat. — Torres Strait, iu 3 to 11 fathoms (Challenger) ; Cape York (J. B. Jukes, in
Brit. Mus.) ; Moreton Bay, Philippine Islands, and Malacca (Mus. Cuming) ; Japan
(A. Adams and Dunker).

After a careful study of the forms above enumerated I can arrive at no other
conclusion than that they all belong to one and the same species. Clementia strangei is
jjerhaps the most peculiar among them on account of the regularity and unusual
development of the concentric ridges. On the contrary, Clementia moretoniensis is
remarkable in having mere indications of such ridges, being merely roughly concen-
trically striated and here and there somewhat plicate. The form is apparently very
varial)le, judging from the series of specimens in the British Museum, no two specimens
being absolutely alike in this respect. On the other hand, the hinge appears to be very
constant in character, and the jDallial sinus and muscular scars are not subject to any
important variation.

It is very probable that the shell described and figured by Chemnitz (Conch. -Cab.,
voh xi. p. 219, pi. cc. figs. 1959, 1960) as Mactra vitreais, the same species as that under
consideration. The fact of it belonging to the genus Clementia has already been
referred to by Philippi, Deshayes, and Pfeifier.

REPORT ON THE LAMELLIBRANCHIATA. 155

Family I s o c A R d 1 1 d ^ (?).

Callocardia, A. Adams.

Callocardia (?) adamsii, n. sp. (PL VI. figs. 7-7h).

Testa valde insequilateralis, cordata, ventricosa, alba, concentrice tenuiter lirata.
Umbones prominentes, magni, iucurvati, baud approximati, longe ante medium coUocati.
Margo dorsi posticus elongatus, declivis, leviter arcuatus, anticus brevior, paulo convexus.
Lunula magna, late cordata, infra umbones leviter depressa, in medio aliquanto prominens,
linea profunde incisa circumdata. Area postica lanceolata, incrementi lineis striata, sub-
concava, bene definita. Dentes cardinales valvse sinistra; duo irregulares, antico elongato
sinuoso, infra umliones sito, postico niiuore obliquo. Valva dextra dente unico elongato
irregulari munita. Ligamentum parvum profunde inter umbones supra marginem situm.

This species is somewhat cordate, a little longer than high, very inequilateral, more
elongated and produced behind than in front. It is rather convex, moderately thick,
white, not glossy, and sculptured with close fine concentric thread-like lirse, which become
mere striae upon the lunule and the posterior dorsal area. The front dorsal margin is a
little excurved and rather abruptly descending, the posterior being longer, gently arcuate,
and obliquely inclined, forming together with the upcurved ventral outline a rather more
acute extremity than in front. The lunule is broadly cordate, a little concave imme-
diately beneath the beaks, a trifle elevated along the centre, and cu'cumscribed by a deeply
incised line. The posterior dorsal area is narrow, lanceolate, and defined by subcarinate
ridges extending from the beaks to the hinder extremity. The umbones are much
elevated above the hinge-line, and curve over considei-ably towards the front. They are
not quite adjacent, and terminate in minute smooth glossy apices which curve away some
distance from the centre of the lunule. The hinge-teeth are peculiarly irregular in form,
and not easily described. In the left valve there are two, of which the posterior one is
narrow, oblique, small, and located below the ligament. The anterior forms an inner
raised irregular sinuated and notched edge to the hinge-plate, being separated from the
upper hinge-margin by a deep irregular groove. The right valve has but a single elongate
tooth of a similar irregular conformation as the anterior in the opposing valve. The
ligament is yellowish-brown, rather small, short, and situated deeply between the
umbones. The interior of the valves is opaque white in parts, and bluish-white else-
where, and exhibits numerous largish shallow pits or punctures irregularly disposed. The
muscular scars and the pallial line are rather indistinct.

Length 12f mm., height 11^, diameter 9.

Habitat. — Station 348, south of Sierra Leone, at a depth of 2450 fathoms.

It is doubtful whether this species really belongs to the genus Callocardia. It
agrees with it in its cordate form, the curved over beaks, and the impressed line

156 THE VOYAGE OF H.M.S. CHALLENGER.

circumscribing th(> luiuile. However, the dentition is not absolutely identical, although
after the same type.

In Callocardia guttata,^ dredged off the island of Quelpaart, south of the Korea, in
48 fathoms, the only species as yet described, and of which but a single left valve exists,
there are two cardinal teeth, of which the posterior is long, lamellar, slightly arcuate,
parallel with the dorsal line, and having the edge produced into two denticles. The
anterior tooth is very complicated, being thin, prominent, angularly bent in the middle,
with the margin produced into four unequal cusps. The ligament is rather long, and
situated in a narrow deep groove upon the margin, so that if the valves were closed Ijut
very little of it would be visible.

It will thus be seen that the present species differs somewhat from Callocardia in
dentition, in its coarser sculpture, and its more external ligament. It might perhaps with
the same propriety be considered a large form of Kelliella, agreeing equally well with
that genus in dentition, form, and luuule.

The two following species bear a still closer resemblance to Kelliella both in size and
sculpture, so that it becomes questionable whether there be sufficient ' grounds for
separating that genus from Callocardia.

Callocardia (?) i^acifica, n. sp. (PL VI. figs. 9-9/->).

Testa parva, globosa, tenuis, fragilissima, alba, hie illic zouis angustis pellucidis,
hand conspicuis ornata, concentrice regulariter tenuiterque striata, insequilateraUs,
transversim ovato-rotundata. Margo dorsi posticus subhorizontalis, aliquanto arcuatus,
anticus brevior, niagis obliquus, subrectus. Latera rotundata, anteriori angustiori.
Umbones prominentes, valde incurvati, baud contingentes, partem anticam versus eonspicue
versi, ad apicem opaco-album obtusi. Lunula magna, hand impressa, stria tenui
circumscripta, cordata, lateriljus valde convexis. Cardo ex dente unico obliquo
lamellar! in valva sinistra pone umbonem sito, sulcoque elongate antice irregulari
profundo compositus.

The shell is longer than high, excessively thin and fragile, oblong rounded, a little
narrower in front than behind, and consequently more acutely curved. It is jDrettily
ornamented with milky white and pellucid zones, and sculptured with fine concentric striae.
It is ineciuilateral, the anterior side being much shorter than the posterior, considerably
inflated, and glossy. The umbones arc large and prominent, not contiguous, and much
curved over towards the lunule. The latter is large, not at aU sunken, heart-shaped,
the outline, defined by a very fine stria, Ijeing much excurved. The dorsal margin is
long behind, moderately arcuate and but very, slightly ol)lique ; in front it is shorter, less

' A. Adums, Ann. and Mag. Nut. Hist., 1864, vol. xiii. p. 307.

REPORT ON THE LAMELLIBRANCHIATA. 157

curvotl, ami decideclly more descending. Tlierc is in the left valve a single oblique lamellar
tooth which is situated behind the umbo forming the posterior boundary to a narrow deep
groove which is as it wore lobed in front and extends a little beyond the apex of the beak.
The muscular scars and pallia! impression are very indistinct.

Length 4i mm., height 4, diameter 3.

i/a^iirt^.— Station 244, Mid North Pacific Ocean, at a depth of 2900 fathoms; red clay.

A single specimen from the above great depth (nearly three and a third miles) was
dredged up perfect, both as regards the shell and animal. In endeavouring to open the
valves in order to determine the genus some slight damage was done, and it became
necessary to boil the specimen so that the adductor muscles should relinquish their hold
and allow the valves to separate. Unfortunately, the hinge-plate of the right valve was
destroyed, but, judging from the left valve, its construction must have been all but
identical with that obtaining in the following species.

CaUocardia (?) atlantica, n. sp. (PI. VI. figs. 8-8?>).

Testa CallocardicB pacificce similis, sed brevior, seque longa ac alta.

Beyond the difference in form there is very little to distinguish this species from
CaUocardia pacijica. It is a very remarkable fact that shells so similar should exist at
such great depths, at such remote localities, which, however, are situated almost upon
the same parallels.

On placing side by side specimens of KeUiella miliaris from Hardanger Fiord,
Norway, kindly furnished me by the Rev. A. M. Norman, with the Challenger examples
of this species, and others from Davis Strait obtained by the " Valorous " expedition,
and regarded by Dr. Gwyn Jefireys as the fry of Isocardia cor, I observe certain
distinctions. In the first place, I have never seen or heard of a KdUellct from Norway
attaining to the size (4 mm.) of the specimen from Station 73. In the next place, I
perceive a difference in form, the ventral outline of these specimens being decidedly
bulged or more excurved than that of KeUiella. In addition to this, there is a slight
variation in the dentition, which accurate figures alone could well explain, and finally,
in the minute specimens in question, I find a slight dorsal ridge, which marks off a
posterior area, of which ridge I can discover no trace in KeUiella.

The fry of CaUocardia adarnsii must resemble this species very closely in form
and dentition, but, judging from the apices of the known specimens, which may not,
however, be full grown, it would be more strongly concentrically sculptured.

Length and heio-ht 4 mm.

Habitat. — Station 73, west of Azores, in 1000 fathoms; also Station 78, off San
Miguel, at a depth of 1000 fathoms.

158 THE VOYAGE OF H.M.S. CHALLENGER.

Family C a n D 1 1 D ^:.
Subfamily Cardiin.e.
Cardium, Liune.
Cardium (Acanthocardium) setosum, Eedfield.

Cardium setosum, Eedfield, Ann. Lyceum Xat. Hist, New York, 1846, vol. iv. pi. v. p. 168,
pi. xi. figs. 1, a, h, c.

Habitat. — Station. 212, soutli of the Philippine Islands, in 10 to 20 fathoms; sand.

This interesting species was originally described from Chinese examples.

With it, in my opinion, should be united the Cardium latum of Chemnitz, Reeve,
Romer, and other authors, which appears to be a different shell from that described by
Born. The latter author's description (Test. Mus. Vindobon., p. 48) certainly accords
better with the well-known. Cardium bullatum of the West Indies than with the shell
identified by the above authors.

Having very carefully compared the shell figured by Reeve (Conch. Icon., fig. 21)
with examples of Cardium setosum, I am unable to discover any distinctions, except a
slight difference in form, a character veiy variable in many species of this genus.

Cardium [Acanthocardium) papillosum, Poli.

Cardium papillosum, PoU, Test. utr. SiciI.,vol. ii. p. 56, pi. xvi. figs. 2-4.

Cardium papillosum, Eeeve, ConcL Icon., voL ii. fig. 111.

Cardium papillosum, Philippi, Enum. Moll. Sicil., voL i. p. 51, vol. ii. p. 38.

Cardium papiJlosum, Hanley, Cat. Eec. Shells, p. 137, pi. xvii. fig. 6.

Cardium papillosum, Jeffreys, Brit. Conch., vol. ii. p. 275, vol v. pi. xxxv. fig. 1.

Cardium {Acanthocardium) papillosum, Eomer, Conch. -Cab., ed. 2, p. 32, pi. xi. fig. 1.

Habitat. — Station 75, off Fayal, Azores, in 50 to 90 and 500 fathoms ; and off
Tenerife,^Canarie.s, in 70 fathoms.

Cardium [Acanthocardium) sueziense, Issel (PI. VIII. figs. 2-26).

Cardium sueziensis, Issel, Mai. Mar. Kosso, p. 76, pi. iii. fig. 4 (not good).
Testa allia, iuaequilateralis, mediocriter convexa, ii'regulariter rotundata, postice lata,
oblique subtruncata, antiee angustior, arcuata, costis radiantibus circiter 25 con-
fertim' tuberculatis ornata. Margo dorsi anticus brevis, arcuatim descendens, posticus
rectiusculus, sursum incliuatus. Umbones parvi, paulo supra marginem dorsalem
producti. Pagina interna alba, radiatim sulcata, ad marginem fortiter denticuJata.

This species is about as long as high, irregularly rounded, narrower in front than
behind, rather inequilateral, pure white, and ornamented with about twenty-five tuber-

REPORT ON THE LAMELLIBRANCHIATA. 159

culated ribs. These are very much broader than the intervening grooves, and of different
%vidths, the widest being dov\Ti the anterior side, and the narrowest at the opposite end.
The tubercles upon them are closely packed and compressed, or, in other words,
transversely elongated, a feature especially observable upon the stoutest ribs. The
beaks are moderately prominent, well tui-ned over towards the front, and decidedly
antemedian. The dorsal margin descends very suddenly in a slight curve in front, but
rises somewhat in a straightish line behind the beaks. The anterior end is broadly
arcuate, gently rounding into the ventral margin, which is also widely curved. The
hinder extremity has a tendency to oblique truncation, although the l^oundary is in
reality on a gentle curve. It joins the dorsal margin in a rounded angle having a high-
shouldered appearance, the result of the rising of the dorsal line. The interior is white,
radiately narrowlj^ grooved and rather strongly dentate along the margin.

Length 7 mm., height 7, diameter 5.

Habitat. — Off Levuka, Fiji Islands, in 12 fathoms (Challenger) ; Gulf of Suez (Issel
and MacAndrew).

This very pretty little shell, which probably attains a larger size, is chiefly
characterised by its form and the closely packed transverse tubercles upon the ridges.
Having carefully compared specimens from Fiji with examples from the Gulf of Suez,
I am unable to discover any distinctions except that in the former there is an absence
of coloiu', due probably to their dead condition.

Cardium (Bucardium) mirahile, Deshayes (PL VIII. figs. 1— Ic).

Cardium mirahile, Deshayes, Proc. ZooL Soc. Lond., 1854, p. 332.
Habitat. — Station 203, PhOippine Islands, in 12 to 20 fathoms ; mud.

This beautiful species bears some resemljlance to Cardium asiaticum^ but has fewer
and stouter ribs, has not the posterior prominence of that species, and is remarkable on
account of the short white spines upon the costas.

Cardium (Bucardium) tenuicostatum, Lamarck.

Cardium tenuicostatum, Lamarck, Aniru. sans vert, ed. 2, vol. vi. p. 392.

Cardium tenuicostatum, Delessert, Eecueil, pL xi. figs. 6, a^c.

Cardium tenuicostatum, Sowerby, Conch. 111., figs. 36, 62.

Cardium tenuicostatum. Reeve, Conch. Icon., vol. ii. fig. 50.

Cardium tenuicostatum, Romer, Conch.-Cab., ed. 2, p. 69, pL xii. figs. 6, 7.

Cardium pallidum, Romer, loc. cit., fig. 92.

Cardium radiutum, Edmer, loc. cit., fig. 89.

Habitat. — Port Jackson, Sydney, in 2 to 10 fothoms ; also Station 208, Philippine
Islands, in 18 fathoms.

160 THE VOYAGE OF II. M.S. CHALLENGER.

This species is found at the Philippine Islands, on the east and west coasts of Australia,
and also on the shores of Tasmania. I fail to appreciate the distinctions pointed out by
Eeeve with regard to Cardium j^ctUidum and Cardium radiatvm.

All the forms have exactly the same kind of epidermis, and diifer only in the amount
of colour and somewhat in outline. Some of the specimens from Port Jackson are very
pretty, having the riljs pinkish -red interrupted hy concentric pale irregular zones.
Other examples from Swan Piver are more or less suffused throughout with a pinkish
tint, the interior exhibiting a vivid purple-pink below the beaks.

Cardium {Bucardium) an st rale, Sowerby.

Cardium australc, Sowerby, Proc. Zool. Soc. Lond., IStO, p. 105.
Cardium ausfrale, Sowerby, Conch. 111., figs. 12, 12*.
Cardium, australe, Eomer, Conch.-Cab., ed. 2, p. 70, pi. xii. fiprp. 8, 9.
Cardium australe, Reeve, Conch. Icon., vol ii. pi. six. fig. 97.
Cardium jmlcJirum, Eeeve, loc. cit., fig. 98.

Habitat. — Off Levuka, Fiji, in shallow water ; and Station 208, Philippine Islands,
in 18 fathoms.

This species has already been recorded from the coasts of Australia and China, from
the Cape of Good Hope, the island of Kodriguez, and the Mauritius. Apparently it
never attains nearly so large a size as Cardium tenuicostatum, which it closely
resemliles in many respects. It is, however, rather higher in jDrojJortion to the length,
has more prominent iimbones, is narrower above, smoother, more glossy, differently
coloured, has stronger sculpture between some of the posterior riblets, which are not
carinate clown the middle, and it is not apparently adorned with an epidermis, judging
from the series of specimens which I have examined.

A single .shell from Station 208 constitutes a peculiar variety, differing from the
jiormal form in being higher and narrower, and rather more finely and more numerously
costate anteriorly and upon the central portion of the valves. It is also remarkable in
having the umljo of the left valve stained purplish-red, that of the right being white.

Cardium (Bucardimn) midtispinosum, Sowerby.

Cardium multispinosum, Sowerby, Proc. Zool. Soc. Lond., 1840, p. 106.

Cardium midtisjnnosum, Sowerby, Conch. 111., figs. 38, a, h.

Cardium multispinosum, Hanley, Eec. Biv. Shells, pp. 137 and 3G3, pi. xvi. fig. 58.

Cardium vmltispinosum, Eeeve, Conch. Icon., vol. ii. pi. ii. fig. 10.

Cardium multispinosum, Roiner, Conch.-Cab., ed. 2, p. 67, pi. xii. figs. 1, 2.

Habitat. — Stations 188 and 189, both west of Cape York, North Australia, at dephs
of 28 and 25 fathoms ; green mud.

REPORT ON THE LAMELLIBRANCHIATA. 161

This species was found at low water in sandy mud and also at a depth of from 6 to
25 fathoms at the Philippine Islands by Mr. Cuming, and Mr. J. Reeves presented to the
British Museum specimens collected by himself on the coast of China.

Cardmm (Bucardium) lyulchellum, Gray.

Cardmm striatidiim, Sowerby, Proc. Zool. Soc. Lond., 1840, p. 105.

Cardium striatulum, Sowerby, Conch. 111., figs. 16 and 45.

Cardium striatulum, Reeve, Concli. Icon., vol. iL fig. 60.

Cardium striatidum, Hutton, Man. New Zealand Moll., p. 153.

Cardium pukhellnm, Gray, Dietienbach's Travels in New Zealand, vol. ii. p. 252.

Cardium pulchellum, Reeve, Concli. Icon., fig. 42.

Cardium novce zelandice, Deshayes, MS. in Mus. Cuming (?).

Habitat. — Station 162, off East Moncoeur Island, Bass Strait, in 38 to 40 fathoms ;
Station 161, off Port Philip, South Australia, in 38 fathoms; and at Port Jackson, New
South Wales, in 2 to 10 fothom.s.

I cannot agree with Reeve, Augas, and Hutton in distinguishing Cardium pidchellum,
Reeve, from this species. I can discover no difference of sculpture, and the extra bright-
ness of the red rays is unimportant and variable. The name striatulum being preoccupied
by Brocchi in 1814 for a fossil species, that proposed by Gray is here retained. This
species is very abundant in some parts of New Zealand, and apparently the only one
found on the shores of that country. It ranges as far north as Port Jackson on the
Australian coast, from which place it has been previously recorded by Mr. G. F. Angas.

Cardium [Papyridea) hullatum, ((Linn. ?) Chemnitz).

Sohn hullatus (?), Linn^, Syst. Nat., ed. 12, p. 1115.

Solen hidlatus, Chemnitz, Conch.-Cab., vol. vi. p. 65, pL vi. figs. 49, 50.

Cardium hidlatum, Reeve, Conch. Icon., vol. ii. fig. 8.

Cardium I^Papyridea) hullatum, Romer, Conch. -Cab., ed. 2, p. 74, pi. xii. figs. 13-16.

Cardium (Fidvia) bullaft/m, Chenu, Man. de Conch., vol. iL p. 109, figs. 500-502.

Cardium soleniforme, Bruguiere, Ency. Moth., vol. i. p. 235.

Cardium soleniforme, "Wood, General Conch., p. 233, pi. Ivi fig. 3.

Cardium aspersmn, Sowerby, Proc. Zool. Soc. Lond., 1833, p. 85.

Cardium aspersum, Sowerby, Conch. 111., fig. 15.

Cardium asperum, Romer, loc. cit., pp. 76 and 122.

Cardium hiulcum, Reeve, lor. cit., fig. 123 (cxeniplum distortum).

Cardium hiulcum, Chenu, Man. Conch., vol. ii. p. 109, fig. 499.

Cardium latum. Born., probably {non auctorum) Test. Mus. Vindobon., p. 48, pi. iii. fig. 8.

Habitat. — Bahia, Brazil, in 7 to 20 fathoms.

(zool. chall. EXP. — PAET XXXV. — 1885.) Jim 21

162 THE VOYAGE OF H.M.S. CHALLENGER.

This well-known "West Indian shell has already been recorded from several islands
belono-ing to that group and from St. Elena and Monte Christe on the west coast of
Central America. The shell described by Reeve as Cardium hiulcum, from an unknown
locality, is unquestionably a mere distorted half-grown example of this species. In the
Report on the Mollusca of the west coast of America, Dr. P. P. Carpenter states that he
considers Cardium asperum perfectly distinct from Cardium hullatum. In this opinion
I cannot concur, for, having closely studied the two forms, I fail to discover any con-
stant and sufficient reasons for separating them specifically.

Cardium (Papyridea) semisulcatum, Gray.

Cardium semisulcatum, Gray, Annals of Philosophy, 1825, vol. ix. p. 137.

Cardium 7-riirjiculnm, Sowerby, Proc. Zool. Soc. Lend., 1848, p. 106.

Cardium ringicidum, Sowerby, Conch. 111., fig. 11.

Cardium ringiculum, Hanley, Rec. Biv. Shells, p. 136.

Cardium ringiculum, Reeve, Conch. Icon., vol. ii. fig. 115.

Cardium ringiculum, d'Orbigny, Sagra's Hist, de Cuba, vol. ii. p. 305.

Cardium {Papyridea) ringiculum, Romer, Conch.-Cab., ed. 2, p. 76, pi. xiL figs. 17, 18.

Cardium petitianum, d'Orbigny, op. cit., p. 309, pi. xxvii. figs. 50-52.

Habitat. — Simon's Bay, Cape of Good Hope, in 15 to 20 fathoms.

Gray's name has hitherto been overlooked. In the British Museum the types which
he described are stUl preserved, and accord with respect to colour with his brief
diagnosis. They consist of five odd valves, one of them being totally white, two pale
lemon-yellow, the fourth light red, and the remaining specimen white anteriorly and
pink behind.

I am inclined to think with Reeve that this species does not occur at Ceylon as
stated by Sowerby, but that it wUl be found restricted to the Atlantic. It is very
interesting to find this West Indian form ranging eastward as far as the Cape.

Cardium (Papyridea) transversale, Deshayes (PL VIII. figs. 3-36).

Cardium transversale, Deshayes, Proc. Zool. Soc. Lond., 1854, p. 333.

Habitat. — Station 75, ofi" Fayal, Azores, at a depth of 4.30 fathoms; and ofl'
Tenerife, Canary Islands, in 70 fathoms (Challenger) ; Alboran Island (Deshayes).

This species, as far as at present known, is of small size, the largest specimen
examined being only 6 mm. long, 4 high, and 3 in diameter. It is oblong, rounded
anteriorly, and obliquely truncated behind. It is very inequilateral, white in front and

REPORT ON THE LAMELLIBRANCHIATA. 163

bumt-brown posteriorly, where some of the radiating costse are spotted with white. The
sculpture consists of about twenty-three ribs of different thickness, a few upon the
posterior side being more elevated and thicker than the rest. Four or five others
situated on the same side, but above those referred to, arc ornamented with strong white
scales. The interstices between the costse exhibit rather well-marked lines of growth,
which cross the ribs upon the anterior portion of the valves, thus producing a slightly
nodose appearance. The umbones are small, but very slightly raised above the hinge-
line, and located a long way in advance of the middle. The hinge is composed of a
single prominent cardinal tooth in the left valve, which fits in between two denticular
prominences in the right. The anterior lateral teeth are much approximated to the
cardinals, the posterior being very remote. The interior of the valves is coloured like the
exterior, deeply grooved and strongly dentate at the margin.

Cardium (Lcevicardium) norvegicum, Spengler, var.

Cardium norvegicum, Spengler, Forbes and Hanley, Brit. Moll., vol. ii. p. 35, pL xxxi.

figs. 1, 2.
Cardium norvegicum, Rtimer, Conch. -Cab., ed. 2, p. 83, pi. xiii. figs. 3-6.
Cardium 7wrvegieum, Jeffreys, Brit. Couch., vol. ii. p. 294, vol. v. pi. xxxv. fig. 7.

Habitat.- — St. Vincent, Cape Verde Islands, in 7 to 20 fathoms.

The few shells from this locality are scarcely so oblique and pointed behind as more
northern specimens, the epidermis is thinner, and the valves are rather more vividly
spotted with a pinkish-brown tint. The species has not previously, I believe, been
found so far south. The West Indian species, Cardium glabratum, Romer ( = Cardium
loevigatum, Reeve, non Linn.), might almost be considered a variety.

Cardium (Fraginn) medium, Linne.

Cardium medium, Linn^, Syst. Nat., ed. 12, p. 1122.

Cardium medium, Wood, Index Test, pi. v. fig. 5.

Cardium medium.. Reeve, Conch. Icon., vol. ii. fig. 30.

Cardium (Fragum) medium, Romer, Conch.-Cab., ed. 2, p. 102, pL iv. figs. 5-7.

Habitat. — Station 113a, off Fernando Noronha Island, north-east of Brazil, in
25 fathoms ; volcanic sand and gravel.

This is a well-known West Indian species, and is closely represented on the west side
of America by Cardium biangidatum and Cardium planicostatum.

164 THE VOYAGE OF H.M.S. CHALLENGER.

Cardium (Fragum) fornicatum, Sowerby.

Carditim foy-nicatum , Sowerby, Proc. Zool. Soc. Loud., 1840, p. 110.
Cardium fornicatum, Sowerby, Concb. 111., fig. 48.
Cardium fornicatum, Eeeve, Conch. Icon., pi. xx. fig. 110.
Cardium adamsii, Eeeve, Voy. " Samarang," p. 77, pi. xxii. fig. 2.

Habitat. — Station 172, ofl'Nukalofa, Tongatabu, in 18 fathoms ; coral mu<l.

This charming species was obtained off the Bornean coast during the voyage of the
" Samarang." It is easily recognised by the numerous slender costellaj, which are most
beautifully adorned with very numerous short hollow spines.

Cardium (Fragum) imbricatum, Sowerby.

Cardium imbricatum, Sowerby, Proc. Zool. Soc. Loud., 1840, p. 110.
Cardium imbricatum, Sowerby, Conch. 111., fig. 48.
Cardium imbricatum, Eeeve, Conch. Icon., vol. ii. fig. 28.

Habitat. — Off Cape York, North Australia, in 3 to 12 fathoms (Challenger)'; Swan
River, West Australia (Sowerby).

Cardium (Fragum) torresi, n. sp. (PL VIII. figs. 4-46).

Testa parva, paulo in^quilateralis, mediocriter globosa, tenuis, albida, radiatim
tenuissime costellata, hie illic radiatim granulata, et liris transversis crebris inter costeUis
cancellata. Umbones magni, prominentes, paulo ante medium collocati. Latus anticum
rotundatum, posticum subquadratum, inferne subangulatum.

This is a very beautiful little shell, and readily recognised by its remarkable
sculpture. It is a little longer than high, rather ventricose, slightly inequilateral, white,
thin, and very beautifully sculptured with about seventy very fine thread-like radiating
lines, separated by equally fine grooves which have very numerous cross-bars producing
a punctured appearance. These cross-bars do not form a concentric series, but are
irregularly disposed, and, like the costellse, are obsolete on the dorsal areas. In addition
to this ornamentation the valves are further adorned with radiating series of small
tubercles or blunt spines which fall not upon the costse as usual, but in certain of the
interstices at rather unequal distances apart.

The anterior side is a trifle shorter than the posterior, and broadly rounded, as is also
the lower margin. The hinder side is slightly narrower than the front, and more or less
truncated, joining the ventral outline at a slight angle. The umbones are fairly

KEPORT ON THE LAMELLIBRANCHIATA. 165

prominent, well incurved and glossy at the apex. The interior of the valves is white,
faintly radiately substriated, minutely denticulated upon the margin, and exhibits a
slight ridge or angulation from the beaks to the lower hinder extremity.

Length 4|- mm., height 4\, diameter 3|.

Habitat. — Station 188, south of New Guinea, at a depth of 28 fathoms; green mud.

The above dimensions do not probaljly indicate the maximum size attained by this
species, but the peculiarity of the sculpture is such as to warrant the description of these
possibly young shells. The position of the tubercles in the grooves, and not upon the
intervening costellae, is most unusual.

Family Verticordiid^.

Verticordia, Searles Wood.

This genus and Pecchiolia of Meneghini closely resemble each other in general
outward appearance and as regards the hinge-characters, and possibly may be identical
from a generic point of view, although this has still to be clearly demonstrated. If they be
the same, it then becomes questionable whether the more recent name Pecchiolia should
be adopted, as has been done by Jeffreys and others, on the ground that Verticordia was
preoccupied in botany. Considering the difference of opinion upon this point, the
uncertainty of their identity, and that the name Verticordia has been employed by such
excellent authorities as Fischer, Dall, and Stoliczka, I prefer to adopt the views of these
writers rather than follow that expressed by Dr. Gwyn Jeffreys in this matter. I
should here remark that the last named author not only considers the two forms in
question identical, but unites with them Lyonsiella of Sars, a genus, as already pointed
out by Heilprin,^ which is very different both as regards the shell and animal. Our
knowledge of the soft parts of Verticordia is very incomplete at present ; but the
observations of A. Adams ^ show that they differ from those of Lyonsiella in more than
one particular.

The following species I regard as true Verticordice : — (l) Verticordia cardiiformis,
J. Sowerby ; (2) Trigonulina ornata, d'Orbigny ; (3) Verticordia novemcostata, Adams
and Reeve; (4) Hippagus acriticostatus, Fhi\ii)]}i ; (5) Verticordia deshayesiana, Yischev;
(6) Verticordia japonica, A. Adams ; (7) Verticordia multicostata, A. Adams ; (8)
Verticordia granulata, Seguenza ; (9) Verticordia coelata, Verrill ; (10) Verticordia
australiensis,^VQ\t\i; (11) Verticordia Jischeriana,'Da}t\.; (12) Verticordia elegantissima,
Dall; (13) Verticordia arenosa, Smith; (14) Verticordia^ quadrata, Smith; (15)

1 Proc. Acad. Nat. Sci. Philad., 1881, p. 423. 2 ^,„i. and Mag. Nat. Hist., 1862, ser. 3, vol. ix. p. 224.

166 THE VOYAGE OF H.M.S. CHALLENGER.

Pecchiolia gibbosa, Jeflfreys ; (IG) Pecchiolia angnlata, Jeffreys ; (17) PecchioUa tornata,
Jeffreys; (18) Pecchiolia simiosa, Jeffreys.

Of these Nos. 2 and 3 appear to be identical, and Nos. 5 and 6 also constitute but
one and the same species ; but whether or not No. 4 belongs to the same species at
present I am vmcertain ; but that Verticordia multicostata, A. Adams, is not the same
as Verticordia granidata, Seguenza, as stated by Jeffreys, I feel fully convinced if
any reliance is to be placed upon the figures of the latter species in the Journal de
Conchyliologie. The form of the Japanese shell is different, and the ribs twenty-six in
number, or six more than mentioned by Seguenza. His specimen, however, may have
been imperfect, which would account for the difference of outline.

The following species have been assigned to this genus, but in my opinion they
belong to LyonsieUa, namely, — Pecchiolia insculpta, Jeffreys ; Pecchiolia siibquadrata,
Jeffreys ; Pecchiolia ahi/ssicola, Sars ; and LyonsieUa gemma, Verrill.

All of them have the hinge-line in both valves destitute of teeth, and the ligament
internal, and in two instances it is stated to be supported by an ossicle. Although in
the case of LyonsieUa gemma this is not mentioned, there seems to be every probability
of its being present. Jeffreys does not describe the hinge of his Pecchiolia inscidpta, but
having had an opportunity recently of examining the type, I find it corresponds with that
of LyonsieUa in every respect.

Verticordia ornata (d'Orbigny), var.

Trigonulina ornata, d'Orbigny, in Sagra's Hist, de Cuba, vol. ii. p. 292, pi. xxvii. figs. 30-3.3.
Trigoniluna oi-nata, Chenu, Man. de Conch., vol. ii. p. 169, fig. 8-13.
Verticordia ornata, Pischer, Journ. Conch., 1862, vol. x. p. 380.
Verticordia ornata, Dall, Bidl. Mus. Comp. Zool., vol. ix., No. 2, p. 105.

Habitat. — Station 33, off Bermuda, in 435 fathoms ; coral mud.

Two right and one left valves from this locality differ slightly in form and in the
greater number and more slender character of the ribs. These are twelve in number, two
of them on the hinder dorsal slope, being separated from the rest by a broad unribbed
space. The ventral margin is somewhat angular at the middle, curved upward in front
and obliquely truncate behind, forming with the arcuate dorsal margin a rather acute
extremity. The cardinal tooth of the right valve is very strong and prominent, and the
posterior dorsal edge is vevj deeply grooved for the reception of the margin of the left
valves, in which the margin of the lunule is much thickened, forming a sort of tooth,
which fits into a pit in front of the denticle in the other valve. The ligament is in a
groove under the dorsal margin behind the umbones, and is supported in both valves by
a distinct ridge. The distribution of this species is very remarkable, it having been
recorded from the West Atlantic, California, and the China Seas.

REPORT ON THE LAMELLIBRANCHIATA. 167

Verticordia deshayesiana, Fischer.

Verticordia deshayesiana, Fischer, Jouru. de Conch., 1802, vol. x. p. .3.'), pi. v. figs. 10, 11.
Verticordia japonica, A. Adams, Ann. and Mag. Nat. Hist., 1862, ser. 3, vol. ix. p. 2M.

Habitat. — Station 122, oft" Pernambuco, in 350 fathoms; also Station 185, east of
Cape York, North Australia, in 155 fathoms.

A single valve from each of the above localities is all that was obtained of this species.
They are of the same convex character as the shells described by Fischer and Adams, and
not so compressed as Verticordia cardiiformis from the Crag, which is considered
identical byJefi"reys. I have never seen a specimen of Philippi's Verticordia acuti-
costata, but, judging from his description and figure alone, I am not convinced that it is
the same species as Verticordia deshayesiana. His description and figure of the costse
do not accord with the species before me.

Verticordia australiensis, n. sp. (PI. XXV. figs. 6-66).

Testa tenuissima, parva, late cordata, insequilateralis, alba, tenuiter radiatim lirata,
liris parum elevatis, minutissime granulata. Margo dorsi posticus leviter arcuatus,
obliquus, anticus infra umbones excavatus. Ventris margo in medio acute rotundatus,
utrinque valde adscendens. Umbones prominentes, ad apicem aliquanto obtusi, modice
ante medium siti.

This species is small, very fragile, white, rather inequilateral, broadly heart-shaped,
longer than high, and moderately convex, and exhibits a very faint depression at the
posterior end from the beaks to the ventral margin. It is, as seen under the microscope,
everywhere minutely granular, and ornamented with fine, very slightly raised, radiating
lirse, which are about twenty-four in number and subequidistant. The dorsal margin is
oblique on both sides, longer posteriorly than in front, and a little excurved, being
decidedly excavated anteriorly beneath the beaks. These are fairly prominent, rather
large at the apex, curved towai'ds the front, and situated decidedly in advance of the
centre. Both ends of the shell are narrowed, especially the anterior, and sharply
rounded as is the lower outline at the middle, which is much ascending on both sides.
The interior is glossy and the muscular scars and the pallial line not discoverable. The
hinge is composed of a single tubercular tooth in the right valve immediately beneath
the umbo, which fits into a corresponding break in the hinge-line in the left valve, behind
which there is an indistinct tooth. The posterior dorsal margin of the right is also
distinctly grooved for the reception of the acute edge of the left.

168 THE VOYAGE OF H.M.S, CHALLENGER.

Length 3f mm., height S^, diameter 2^.

Habitat. — Station 185b, east of Cape York, North AustraUa, at a depth of 155
fathoms ; coral sand.

This species differs from Verticordia multicostata, A. Adams, in form and the much
less pronounced lirse.

Verticordia ivoodii, n. sp. (PI. XXV. figs. 7-7&).

Testa ventricosa, insequilateralis, tenuis, irregulariter obtusatim cordata, sordide albida,
epidermide dilute fuscescente subarenacea induta, radiatim inconspicue lirata, seque longa
ac alta, intus margaritacea, obsolete radiatim substriata. Margo dorsi anticus brevis,
prope umbones leviter excavatus, parum obliquus, posticus longior, paulo arcuatus,
subhorizontalis. Margo ventralis dorsali multo angustior, rotundatus, lateribus vix
convexis junctus. Umbones magni, prominentes, antice incurvati, baud acuti, aliquanto
ante medium collocati. Lunula parva, depressa, cordiformis. Dens cardinalis valvse
dextrse prominens, tuberculiformis, mediocriter magnus. Ligamentum lineare,
marginale, partimque internum. Cicatrix anterior profunda, postica et linea pallii
indistinctee.

This shell is about as long as high, very thin, rather ventricose and inequilateral.
It is obliquely obtusely subcordate, dirty white, and clothed with a most remarkable
pseudo-epidermis, which to the naked eye has a pale brown granular or sandy appearance.
Under the microscope the surface is seen to be covered with small granules, arranged
pretty regularly in numerous close-set radiating series, and being transparent, when held
up to the light, giving to the valves a punctate appearance as if pricked -^-ith a needle.
On washing the surface with very weak dilute acid the granules quickly dissolve, leaving
the surface punctate all over, for each granule apjaears to rest in a minute circular pit.
In addition to this peculiar sculpturing the surface is marked with about thirty radiating
rusty red elevated lines. The outline is broad above, roundly shouldered, and narrows
towards the lower margin. The dorsal line is a little oblique in front, short, and a trifle
concave ; posteriorly it is longer, faintly arcuate, and nearly horizontal. The ventral
margin is rounded, and curves sharply into the somewhat straight sides, of which the
hinder is less jierpendicular than the anterior. The umbones are rather large, prominent,
weU-curved over towards the front, not quite approximated, nor acute. The lunule is heart-
shaped, a little depressed, not circumscribed, and unequally proportioned in the two
valves, two-thirds of it being in the right. The hinge is composed of a single conspicuous,
tubercular, pearly tooth in the right valve, situated below the margin, and separated
from it by a groove, which receives a marginal sub-tooth or thickening in the left valve.

REPORT ON THE LAMELLIBRANCHIATA. 169

The ligament is subexteriial in part and partly internal. The former portion is linear
and extends all along the hinder dorsal margin, and is partly concealed by the right valve
overlapping the left. The internal portion is not nearly so long, also linear and slightly
divergent from the other. The anterior muscular scar is very deep, whilst the posterior
and the pallial line are not noticeable. The interior is dull pearly, and obsoletely
substriated in a radiating manner.

Length 10 mm., height 10^, diameter 8.

Habitat. — Station 122, off Pernambuco, Brazil, at a depth of 350 fathoms ; also
Station 24, off Culebra Island, West Indies, in 390 fathoms.

This species is very remarkable on account of the peculiar character of its sculpture,
its ventricose form, and broad rounded upper angles. I have named it in remembrance
of the late Searles Wood, author of the genus Verticordia.

Verticordia quadrata, u. sp. (PI. XXV. figs. 8-8&).

Testa quadrata, insequilateralis, albida, minute granulata, radiatimque obsolete lii'ata ;
margo dorsi utrinque declivis, antice valde concavus, brevis, postice longior, vix excur-
vatus, subrectus, rotundato-angulatim in latera ambiens. Marao ventris subangulatim
rotundatus, utrinque subrecte adscendens. Lunula cordata, valde excavata. Umbones
prominentes, antice bene incurvati. Pagina interna albo-margaritacea, nitida. Cicatrix
anterior profunda, postica inconspicua.

This species is of a peculiar square form, three of the sides being subequal in length
and the fourth shorter. It is dirty whitish, everywhere covered with a fine granulation,
faintly radiately lirate, decidedly inequilateral, and moderately convex. The anterior
dorsal margin is very concave beneath the beaks and rather oblique, the posterior being
much longer, nearly rectilinear, and equally sloping. The sides converge towards the
base, are straightish (or the posterior is faintly incurved at the middle), run into the
ventral outline in a rather sudden rounded curve, and join the dorsal margins in rounded
angles. The umbones are moderately prominent, much curved over upon the deeply
sunken cordate lunule, and located about one-third of the length from the anterior end.
The interior is pearly white, and exhibits a deep anterior muscular scar and two minute
pits beneath the lunule (in the left valve), the posterior impression being indistinct.
The ligament is partly marginal and partly contained in a narrow groove within the
margin. The hinge-line in the left valve is apparently toothless.

Length 7 mm., height 6|, diameter 5.

Habitat.- — Station 85, off Palma, Canaries ; depth, 1125 fiithoms ; volcanic mud.

This species is finely granulose, like Verticordia woodii, but is smaller, more solid,

(ZOOL. CHALL. EXP. — PART XXXV. 1885.) Mill 22

170 THE VOYAGE OF H.M.S. CHALLENGER,

more quadrate, and has fewer radiating lines. As but a single left valve was obtained
I am unable to complete the description of the hinge ; however, the right valve would
probably have a single tubercular tooth.

Verticordia tornata (Jeffreys) (PI. XXV. figs. 9-96).

Pecchiolia tormita, Jeffreys, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 494.

Habitat. — Station 70, west of the Azores, in 1675 fathoms; also Station 106, Mid
Atlantic, between Sierra Leone and Brazil, in 1850 fathoms.

Of this species only some fragments were described by Jeffreys. Two perfect valves
from Station 70, and a complete specimen from Station 106, were obtained by the
Challenger, and enable me to supplement the description in the Annals.

This species is globose, somewhat Isocardia-Vike, nearly equilateral, but a very little
inequivalve, the right valve very slightly overlapping the left along the ventral margin
and the hinder dorsal slope. The minute tubercles are arranged in more or less regular
radiating series, their irregularity being especially noticeable at the hinder end. The
umbones are well produced, involuted and directed towards the front, and the ligament
is external and placed in a small sunken groove upon the hinge-line behind the
conspicuous prominent tooth in the right valve, and posterior to the thickened termina-
tion of the front dorsal margin in the left.

Length 13 mm., height 1.3, diameter 10.

The somewhat different position of the ligament in this species is, I think, hardly of
generic importance, as the form and granular surface so closely approach Verticordia
ivoodii and Verticordia quadrata, which connect it with typical species such as Verti-
cordia ornata and Verticordia australiensis.

Family T R i D a c N i d .^.

Tridacna, Bruguiere.

Tridacna crocca, Lamarck.

Tndacna crocea, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 10.

Habitat.— Station 186, off Cape York, North Australia, at a depth of 8 fathoms;
coral mud.

The single specimen from the above locality agrees very fairiy with the figure in the
" Conchylien-Cabinet " of Chemnitz referred to by Lamarck. The species of this genus are
extremely puzzling, and I believe that the young of the largest known shell {Tridacna

REPORT ON THE LAMELLIBRANCHIATA. 171

gigas) has never been satis&ctorily sliowu. In tliose large shells the lamellae become
worn down and much incrusted with coralline growth, so that it is impossible to know
what has been the style of ornamentation when young. I should not l)e surprised
if Tridacna squamosa or Tridacna rudis should prove to be the eaxdy stages of this
colossal form.

Family C H A M i D ^.

Chama, Linne.
Chama gryphoides, Linne.

Chama gryphoides, Linn., part. Syst. Nat., ed. 12, p. 11.39.

Chama gryphoides, Poli, Test., vol. ii. p. 172 ; Atlas, pi. xxiii. figs. 3, 4, 20.

Chama gryphoides, PhOippi, Ennm., vol. i. p. 68.

Chama gryphoides, Weinkauff, Concli. Mittelin., vol. ii. p. 150.

Habitat. — Off Tenerife, Canary Islands, in 70 fathoms ; and Station 75, off Fayal,
Azores, at a depth of 450 fathoms.

This species is found in several parts of the Mediterranean, and probably ranges even
farther south than the Canary Islands; indeed Krauss (Siidafrik. Moll., p. 19) has
already recorded specimens collected on the coast of Natal which he con.sidered belonged
to this species. It has also been found fossil in several places {vide Weinkauff, op.
cit., supra).

Chama hrassica, Reeve.

Chama hrassica, Reove, Conch. Icon., vol. iv. pi. vi. fig. .31.
Habitat. — Reefs off Tongatabu (Challenger); Philippine Islands (Cuming).

The upper of the brown rays represented in the above figure occupies a distinct
depression. The interior of this species is for the most part white, tinged and spotted
more or less with purple-pink upon the margin, which is smooth and not crenulated as in
many other species.

Chama sidphurea, Reeve.

Chama sidphurea. Reeve, Conch. Icon., vol. iv. pi. iii. fig. 14.

Habitat. — Station 187, near Cape York, North Australia, in G fathoms (Challenger);
Island of Mindoro, Philippines (Cuming).

172 THE VOYAGE OF H.M.S. CHALLENGER.

The Challenger specimen is somewhat differently coloured from that figured by Reeve.
The spines on the hinder part are white, set upon a rich red ground, those upon the anterior
half of the upper valve being lightish brown at the tips and white at the bases. In this
species the lower valve is angulated down the middle, half, or a little more, being
attached and the remainder arising at an oblique angle. The umbo in this valve is
considerably curved over towards the front and away from the dorsal edge, but not
nearly to the same extent as in Chama multisqxiamosa, an allied form. The interior of
this valve is generally whitish in front, and more or less stained with purple-rose or
purple-browTi upon the hinder portion or non-attached half The upjaer valve has usually
less colour within, generally exhibiting a more or less distinct purplish stain from the
umbo down the hinder central part and some purplish spots upon the outer margin. The
spines upon the exterior of the lower valve vary in colour, being either white, brown,
yellow, or pinkish.

Chama carditceformis (P), Reeve.

Chama carditceformis, Eeeve, Conch. Icon., vol. iv. pi. vi. fig. 33.
Habitat. — Statipn 208, Philippine Islands, in 18 fathoms ; blue mud.

The type of this species in the British Museum has been very much over-cleaned, and
the spines to a great extent worn down so that it is imjjossible to pronounce ^dth cer-
tainty whether the j)retty little specimen from the above locality be without doubt
conspecific. It is of the same Cardita-\\\.e form, but has a p)eculiar colouring. The
short hollow spines in the free valve, which radiate in series from the umbo, have a
pinkish-red spot within at their bases, which are only seen when the shell is placed in a
certain position. The apices of both valves are pink, and the interior of the upper valve
exhibits a broad brown stain upon the hinder half. The figure in the Conchologia Iconica
is far from correct, the spines down the posterior side being greatly exaggerated.

Chama jukesii. Reeve.

Chnma juliesii, Eeeve, Conch. Icon., vol. iv. pi. vii. fig. 39.
Habitat. — Station 186, off Cape York, North Australia, in 8 fathoms ; coral mud.

The type of this species in Cuming's collection was collected by Mr. J. B. Jukes at
Cape Upstart, also on the north coast of Australia. I cannot discover any good reasons
for separating either Chama pellis-phocce or Chama fibula (both of Reeve) from this
species.

REPORT ON THE L4lMELLIBRANC1I1ATA. 173

Chama spinosa, Broderip.

Chaina qiino-<a, Broderip, Trans. Zool. Soc. Loud., vol. i. \t. 306, pi. xxxviii. figs. 8, 9.
Chama spinosa, Ileove, Concli. Icon., vol. iv. fig. 44a.
Chama spinosa, Angas, Proc. Zool. Soc. Loud., 18G7, p. 925.

Habitat. — Port Jackson, Sydney.

A single small specimen only attached to a portion of a Mytihis. Angas observes
that the species is "found attached to rocks at low spring tides." The type shells are
said to have come from Lord Hood's Island in the Pacific Ocean.

Family L u c i N i D yE.

Lucina, Bruguiere.
Lucina columhcUa, Lamarck.

Lucina columbdla, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 230.
Lucina coliimheUa, Hanley, Cat. Piec. Shells, p. 77, pi. ix. fig. 2.
Lucina columhella. Reeve, Concli. Icon., vol. vi. pi. vi. fig. 30.
Lucina columhella, Sowerbj^ Gen. Shells, lig. 6.

Lucina adansoni, d'Orbigny, in Webb and Berthelot's Hist. Ivat. Canaries, vol. ii. part 3,
p. 107, pi. vii. figs. 26-28.

Habitat. — St. Vincent, Cajae Verde Islands, in 7 to 20 fathoms.

This species is also found at the Canary Islands and perhaps as far south as Senegal.
The Challenger specimen is remarkably globular, being 37 mm. in length and height and
34 in diameter.

Lucina lamellata, Smith (PL XIII. figs. 1— 1&).

Diplodonta lamellata. Smith, Proc. Zool. Soc. Lond., 1881, p. 38, pi. v. figs. 1-lc. .

Testa solida, ii-regulariter rotuudata, insequilateralis, autice brevior, angustata, postice
oblic[ue truncata, ad extremitatem rotunde subangulata. Valvse mediocriter convexse,
albidae, epidermide sordide flavescente rugose striata iudutse, lameUis concentricis
conspicuis oruataj, prope marginem dorsi ^josticum depressse, antice lunula lanceolata
profunde excavata instructse. Margo dorsi posticus leviter arcuatus, parum decliAns,
elongatus, antieus brevior, valde obliquus, concavus. Ventris margo rotundatus, anterius
oblique longe ascendens. Ligamentum crassum, hand prominens, in sulco elongato
profundo situm. Dentes cardinis duo in utraque valva mediocriter vahdi, divergentes,
iusequales, lateralis unicus antieus subtuberculiformis. Pagina interna alba, cretacea,
ahquauto rugosa. Cicatrix antica prelongata, angusta, fere usque ad medium testae
extensa, subnitida, striata, postica irregulariter ovalis, latior.

174 THE VOYAGE OF H.M.S. CHALLENGER.

This interesting species is regularly rounded, some\Yliat narrowed in front and
obliquely truncate behind. It is rather solid, considerably inec[uilateral, moderately
convex, and whitish beneath a dirty yellowish epidermis. The sculpture consists of thin
elevated lamellae which are anteriorly less developed than upon the central portion of the
valves, which exhibit a shallow depression down the posterior side, a little below the
dorsal margin, gi^ang the concentric lamellae a somewhat flexuous appearance at this part.
The interstices between the lamellae are rather roughly striated. In front of the acute
umbones the valves have a deep lanceolate elongate lunular excavation defined by very
sharp edges. The front dorsal outline is slightly concave, very oblique, and rather
shorter than the posterior, which is a little convex and not nearly so sloping. The lower
margin is well curved, and ascending obliquely in front, forms together with the dorsal
line a sharply rounded pouting extremity. The hinder end is obliquely truncated, the
shallow dejjression terminating in the middle of the straight edge which joins the dorsal
and ventral margins in rounded angles. The ligament is strong, and placed in a deep
groove occupying the entire length of the hinder dorsal margin, but does not project
above the upper edge of the valves. The interior, with the exception of the hinge-line,
muscular scars, pallia! line, and outer margin, which are glossy, is chalky white, roughish
and subpunctate. The anterior impression is very long and narrow, and falls ol)liquely
within the pallia! line almost to the centre of the valves. The 2:)Osterior is nearly twice
as broad, of an irregular oval form, and radiately striated. The hinge consists of two
cardinal teeth and a single lateral in each valve. Of the former, the posterior in the
right and the anterior in the left are bifid, and the lateral tooth is small and tubercu-
liform.

Length 47 mm., height 42, diameter 24.

Length 39 mm., height 36, diameter 16.

Hahitat. — Station 311, western part of the Strait of Magellan, at a dearth of 245
fathoms ; blue mud.

This species I originally described as a Dvplodonata, having overlooked the presence
of the anterior lateral tooth, which in the young shells then at hand was very incon-
spicuous, and indeed in the adult specimens obtained by the Challenger consists merely
of a slight tuljereular projection. The types were dredged by Dr. Coppinger of H.M.S.
" Alert," in Portland Bay, St. Andrew's Sound ; also on the west side of Southern
Patagonia, in 10 fathoms, on a liottom of hard sand.

Lucina ramsayi, n. sp. (PI. XIIL figs. 2—26).

Testa mediocriter convexa, subseciuilateralis, rotundata, solidiuscula, allja, concentrice
confertim lirata, striis radiantibus in interstitiis subpunctatim sculjjta. Lunula parva,
profunda. Margo dorsi anticus leviter concavus, posticus vix declivis, superne recti-

REPORT ON THE LAMELLIBRANCHIATA. l75

usculus. Umbones parvi, acuti, paulo supra lincam cardinis producti. Pagina interna
baud nitida, punctis paucis profundis sparsis, sulcoque obbque irregulari in medio notata.
Cardo in valva dextra dentc primario infra apicem munitus, dente lateraU antico
elongate, margine exteriori sulco profundo sejuncto. Cicatrix antica superne latiuscula,
inferne angustata, producta, postice irregulariter ovabs. Ligamentum internum,

Tbis species is only a trifle longer tban higb, roundish, roundly sbouldered above,
only moderately convex, fairly strong, not quite equilateral, white, and scvdptured with
fine closely packed concentric lirse which become attenuated and crowded at the sides.
In the grooves between them are innumerable very fine radiating lirae which produce a
punctured appearance. Down the posterior side of the valves is a faintly impressed ray
which is so inconspicuous that it is only seen in certain lights. In front of the beaks is
a small but rather deep lunule, shaped not unlike a short spear-head. The front dorsal
margin is a little concave and sloping, the posterior being less oblique, longer and
straighter. The umbones are small, fairly sharp, but slightly curved over at the tip,
and only a little elevated above the dorsal line. There is a single small tubercular
cardinal tooth under the beak in the right valve under examination, which is all that is
at present known of the species, and the anterior side exhibits a long but not much raised
lateral tooth, separated from the outer margin by a deepish groove. The ligament
appears to be totally internal, and contained in a furrow beneath the posterior dorsal
edge. The dull interior exhibits deep scattered punctures and a strongly marked
irregular impressed line extending obliquely from above the posterior muscular scar to
below the anterior one. The latter is oval at the upper part, but narrowed and produced
downward within the deeply impressed pallia! line, the former being also somewhat oval
in form.

Length 14^ mm., height 13f, probable diameter of the perfect shell 8.

Habitat. — Port Jackson, New South Wales, in 6 to 7 fathoms.

Lucina cristata, n. sp. (PI. XIII. figs. 3-3a).

Testa compressiuscula, tenuis, a^quilateralis, superne breviter rostrata, antice rotundata,
postice subquadrata, albida, lii-is concentricis tenuibis confertis postice lamellatis (lamellis
impressioni radianti interruptis) instructa, in regione lunulse impressa. INIargo dorsi
anticus obliquus, valde excavatus, posticus Eequaliter declivis, rectiusculus. Umlwnes
producti, acuti. Dens primarius unicus valv^e dextrae parvus, laterali utrinque
inconspicuo, remoto.

This species belongs to the typical section of the genus Lucina, characterised by
possessing primary and lateral teeth and by the concentric nature of the sculpture.

176 THE VOYAGE OF H.M.S. CHALLENGER.

Only a single right valve is at present known, and this probably does not represent the
maximum size of the species. It is rather compressed, thin, about equilateral, rather
squarely truncate behind, rounded in front, and gentlj'' curved below. The small acute
umbo being rather prominent, and the dorsal margin in front rather concave, the upper
part of the shell has a peaked appearance. The sculpture consists of fine acute _close-set
lirjB, which become more elevated and lamellar on the posterior side, the lamellae being
somewhat interrupted down the middle by a shallow impression, so that on the posterior
dorsal margin and on a slight angle radiating from the beak to the lower hinder extremity
they form two separate crests. There is a single cardinal tooth in this right valve, and
a small and remote lateral on each side. The lio;ament lies in a narrow a;roove under the
dorsal ed2;e.

Length 4| mm., height 4j, supposed diameter of the perfect shell 2.

Habitat. — Station 185b, east of Cape York, North Australia, in 155 fathoms; coral
sand.

Lucina [Divaricella) irpex, n. sp. (PI. XIIT. figs. 4-4a).

Testa subcircularis, fere sequilateralis, modice convexa, alba, liris elevatis tenuibus
paulo ante medium oblique divaricatis instructa, crassiuscula, spatiis incrementi
coucentrice gradata. Umbones parvi, vix ante medium siti, antrorsum versi, parum
elevati. Margo dorsi postice oblique arcuatus, antice minus curvatus, aliquanto
obliquior. Lunula minuta, profunda. Dens cardiualis in valva dextra unicus, crassus,
obtusus ; dentes duo valvae sinistras parvi, fossa triangulari sejuncti, posteriori valde
obliquo. Fossa ligamenti elongata, utrinque attenuata, intra marginem sita. Cicatrix
antica angusta, elongata. Margo valvarum fortiter serratus.

This species is almost circular, about as long as high, white, almost equilateral,
moderately convex, and ornamented with fine, much elevated ridges or costellfB which
divaricate at an angle of about 45° at a slightly arcuate and oblique line radiating
from the umbo and markino- off from the anterior end rather more than a third of the
valve. The ridges are interrupted at intervals which mark periods of growth, by which
the surface of the valves present a graduated appearance. The grooves, which are equal
to or a little broader than the costella3 between them, are conspicuously deej), especially at
the sides, so that the outline is prettily and strongly dentate. The margin is well curved
all rouud, except along the anterior dorsal slope, where it is a trifle less arcuate. The
beaks are small, curve over towards the front, are but very slightly raised above the
hinge-line, located scarcely in advance of the centre, and have a most minute, deejJy
sunken lunule immediately beneath them. The hinge is composed of a single thick,
obtuse tooth in the rioht valve which fits in between two smaller ones in the left. The
ligament is internal, located in an elongate deepish groove, attenuated at both ends.

REPORT ON THE LAMELLIBRANCHIATA. 177

The anterior muscular impression which falls within the pallial line is narrow, elongate,
and oblique.

Length 15 mm., height 14, diameter 9. Another specimen in the British Museum is
16| mm. long and 16 high.

Habitat. — Cape York, North Australia, in 3 to 12 fathoms.

There is only one other species with which this is likely to be confounded, namely,
Lucina macandrerp, H. Adams, from the Gulf of Suez, which maybe the same species as
Lucina ornatissima, d'Orbigny, hereafter referred to. That species has the umbones
more elevated, the lunule a little larger, the single tooth in the right valve bigger, and
the anterior muscular scar much broader. But another and perhaps the most important
distinction is found in the divaricating ridges. These in Lucina macandrete are a trifle
more slender, granular or serrated along the top, and divaricate at an angle of about 25°
at the central part of the valves. On the contrary, in Lucina irpex the angle of
divergence is much less acute, being about 45°, and the costellse themselves, although
somewhat rugose, are not serrated in the same manner. Lucina ornata, Reeve, is
another allied species, difi"ering from the two previously mentioned in having the
divaricating ridges less elevated, broader and flat-topped, the upper edges of them being
somewhat raised and carinate. The angle at which they diverge is about the same,
namely 45°, as in Lucina irpex. This species [Lticina ornata) has since been described
by Dr. E. von Martens^ under the name of Lucina (Divaricella) angidifera from
specimens collected at the Mauritius. In the British Museum there are three specimens
obtained by Captain Owen, R.N., on the coast of Africa, and others collected by
J. B. Jukes, Esq., at Port Jackson, New South Wales. The type-shell figured by Reeve
(Conch. Icon., fig. 48) is a little abnormal in form, the anterior side being unusually sloping
at the upper part, but not excavated at the lunule as represented in the figure.

Lucina {Cyclas) cumingii, Adams and Angas, is the largest species of the section
Divaricella, and is found in Ceylon, South Australia, Tasmania, Port Jackson, and New
Zealand. It should certainly be held distinct from the West Indian Lucina dentata,
[Wood * = ZifciHtt divaricata, Auct. {non hinn.) = Lucina serrata, d'Orbigny = Z^<cina
chemnitzii, Philippi = ZwcM7a strigilla, Stimpson (probably)]. It difl"ers from that species
in being larger in the adult state, has more acutely divaricating strife, a more elongate
lanceolate lunule, a more external ligament, and a single lateral denticle in each valve on
the anterior side, moderately remote from the cardinal teeth, of which there is not the
slightest trace in Lucina dentata. The front muscular scar, too, is much more elongate,
and the margin of the valves is never serrated, but perfectly smooth.

Care must be taken not to confound the two West Indian forms Lucina dentata and
Lucina quadrisulcata, which has also been named by C. B. Adams Lucina americana.

1 Mollusca dor Insel Mauritius, p. .321, pi. xxii. fig. 14.
^Tellina dentata, Wood, General Concli., p. \^5, \)\. xIfL fig. 7.
(ZOOL. CDALL. EXP. — PAKT x.x.\v. — 1885.) Mm 23

178 THE VOYAGE OF H.M.S. CHALLENGER.

Although sculptured externally in a very similar, in fact, almost precisely the same
manner, they are readily distinguishable by certain characters within the valves. Lucina
dentata has the margin rather coarsely dentate, the denticles at the sides corresponding
with the external raised ridges, l)ut along the ventral edge they are rather more numerous
and finer. In Lucina quadrisulcata the margin appears almost smooth to the naked eye,
but under the lens is found to be most minutely crenulated. Other distinctions in this
species are the presence of a minute lateral denticle in the right valve which is located
nearer the cardinal teeth than that in Lucina cumingii, and fits in between two small
tubercular teeth in the left valve. It is usually rather more globose, has a larger
lunule, which is in the right valve, and much larger cardinal teeth, the anterior in
the left valve being the most conspicuous.

After a very careful examination I am unable to find any distinction in L^icina ehurnea,
Reeve, found at St. Elena, West Columbia, and Panama b)^ Cuming, which will separate it
from the West Indian Lucina quadnsulcata. The form and convexity are the same, and
the lunule, sculpture, dentition, and the minute crennlation of the margin are quite similar.

In the fifth volume of the Voyage dans I'Amerique meridionale, p. 584, 1847, d'Orbigny
gives some observations on all the recent and fossil species of this section (Divaricella) of
Lucina then known to him. Of the former he mentions five, namely Lucina divaricata,
Linn., from the Mediterranean, Lucina quadrisidcata (d'Orbigny), from Brazil and the
West Indies, Lucina serrata, d'Orbigny, also a West Indian form, Lucina sechellensis,
from the Seychelles Islands, and Lucina ornatissima, from the Mauritius.

The two last species, as far as I can ascertain, have never been fully described, but
are merely known by the few observations which M. d'Orbigny makes upon them at the
above reference. From these remarks, owing to their insufiiciency, I am unable to
identify the shells he had before him with any of the better known species. The former,
Lucina sechellensis, approaches in some respects Lucina cumingii, and Lucina ornatissima
maj^ be identical with either Lucina macandrecB or Lucina ii-pex.

Mr. Brazier ^ makes certain observations upon Lucina dentata with which I cannot
agree, at the same time giving a synonymy which in my opinion constitutes an extensive
" lumping" of species. Such distinctions as I have pointed out in the foregoing remarks
must either have altogether escaped his observation, or else he may not regard them of
specific importance. He says, " this species has a very wide range over the earth's
surface, but it does not differ in sculpture." The former statement would be correct if
all the forms which he tabulates under Lucina dentata were really identical. But this
is not the case in my judgment, and I believe any one who Avith great care will study
specimens (not descriptions and figures only) of these species, will arrive at a similar
conclusion, meeting not only with differences of form and dentition but also of sculpture,
which Mr. Brazier has failed to perceive.

■ Proc. Linn. Soc. N. S. Wales, vol. viii. p. 229.

REPORT ON THE LAMELLIBRANCHIATA. 179

Lmcina {Codakia) tigerina (Linne).

Vmiis tigerina, Linnd, Syst. Nat., ed. 12, p. 1133.

Lucina tigerina, Deshayes, Ency. M6th., vol. ii. p. 384.

Ludna tigerina. Reeve, Conch. Icon., voL vi. pi. 1. fig. 3.

Lucina tigerina, Pfeiffer, Conch. -Cab., ed. 2, Veneracea, p. 2G0, pi. xix. figs. 1, 2.

Habitat. — North Atlantic, deep water.

This is a well-knowu Cuban species, and is also quoted by Reeve from the Bay of
Honduras. At times it attains much larger dimensions than are represented by the
above figures, a specimen in the Cumingian collection being 4^ inches in length by
3|- in height.

Lucina {Codakia) interrupta (Lamarck).

Cytherea interrupta, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 318.
Cytherea interrupta, Chenu, lUustr. Conch., pi. xi. figs. 1-1?*.
Lucitia interrupta. Reeve, Conch. Icon., vol. vi. figs. 5, a, h.

Habitat. — Reefs off Tongatabu, Friendly Islands (Challenger) ; Torres Strait (Jukes) ;
Louisiade Archipelago (Brit. Mus.).

This is a more convex species than Lucina tigerina, rounder, proportionally more
solid, and not so roughly sculptured. Its anterior muscular impression is of a different
form, and the pallial line arises in front from the middle of the scar, whilst in Lucina
tigerina it commences higher up.

Lucina (Codakia) pecten, Lamarck.

Lucina peden, Lamarck, Anim. sans vert., vol. v. p. 5-43.
Lucina pecten, Philippi, Enum. MoE. Sicil., vol. i. p. 31, pi. iii. fig. 14.
Lucina pecten, Reeve, Conch, Icon., vol. vi. pi. viL figs. 34 and 35, a, b.
Lucina reticulata, (Poli) Weinkauff, Conch. Mittelm., vol. i. p. IGO.
Lucina obliqita, Reeve, Conch. Icon., vol. vL pi. viii. fig. 42.

Habitat.— Station 113a, off the island of Fernando Noronha, in 25 fiithoms; and
Station 33, off Bermuda, in 435 fathoms.

This species is found in many parts of the Mediterranean, on the west coast of France
and Portugal, at Madeira, the Canary and Cape Verde Islands, at Senegal, Guinea and
St. Vincent, "West Indies. Lucina obliqiia. Reeve, said to be from Chusan, I am unable
to distinguish from this species. The sculpture, hinge, and muscular scars are precisely
similar, both forms have the same oblique pitted line across the centre of the interior of

180 THE VOYAGE OF H.M.S. CHALLENGER.

the valves, aud the form of tlic specimen figured by Reeve as Lucina obliqua is exactly
that of the sheU figured by Philippi.

Only a few small valves about 4 millimetres in length were dredged off Bermuda.
At this young stage they are q^uite as convex as the adult form, from which they differ
in ha\'ing the margin of the valves crenulated within. The outline and hinge characters
are about the same.

Lucina (CodaMa) seminula, Gould (PI. XIII. figs. 5-5a).

Lucina (Myrtea) seminula, Gould, Proc. Bostou Sac. Nat. Hist., 1861, vol. viii. p. 36; Otia
ConeL, p. 174.

Testa minuta, crassiuscula, paulo obliqua, mediocriter convexa, irregulariter rotundata,
ante umbones excavata, alba. Valvse aliquanto insequilaterales, impressione radianti
utrinque notatae, costellis concentricis suljvalidis aliisque minoribus in interstitiis
instructse. Margo dorsi anticus prope umbones conspicue concavus, posticus declivis,
rectiusculus ; margo inferior excurvatus, ad latera leviter sinuatus. Lunula parva,
profundissima. Cardo validus. Dentes cardinales duo divergentes in valva sinistra,
unicus in dextra. Laterales breves, crassi, ab umbonibus sequidistantes. Pagina interna
minute rugulosa, ad marginem incrassatum fortiter dentata.

This minute form is rather solid in texture, slightly oblique in outline, irregularly
rounded, concave in front of the umbones, straightish but oblique on the hinder dorsal
side. It is white, rather inequilateral, with a shallow radiating depression down each
side of the valves, which cause the lateral margins to be somewhat truncate or even
sinuated. The posterior of these is usually more pronounced than that in front. The
sculpture consists of twenty to thirty rather stout and elevated concentric costae, which
gradually become thicker as the shell enlarges, and attenuate at the sides. In the
interstices between them are numerous but more slender radiating lirse, which do not,
however, cross the others. The lunule, although small, is remarkably deeply excavated
beneath the overcurving umljones, each of which is smooth at the bluntish tip. The hinge-
plate is strong. There are two primary teeth in the left valve and one in the right, the
latter falling between the former, which are divergent. The laterals are strong, short,
erect, and about equidistant from the cardinals. The ligament is long, narrow, external,
in a groove on the posterior margin just behind the umbones. Tlie interior of the valves
under the microscope appears to be minutely rugose. The thickened outer margin is
coarsely denticulated, the teeth upon the front and lower margins being a little stronger
than those upon the posterior edge, where at times they are more or less obsolete. The
pallial line is simple and the muscular scars rather large.

Length 2-|- mm., height 2 J, diameter If.

EEPORT ON THE LAMELLIBRANCHIATA. 181

Habitat.— Station 188, south of New Guinea, in 28 fathoms (Challenger); Hong Eong
Harbour (Gould).

There are two or three species which are so closely allied that if a large series of speci-^
mens were got together, in all probability it would be difficult to draw any lines of separa-
tion. All are very similiar in form, agree in having a strong depression down the hinder
side of the valves and a feebler one in front, and differ chiefly in the coarseness of the
cancellation of the surface. Lucina pisum, Reeve, from Port Essington, is the most strongly
sculptured of all, the radiating costse being few in number, and as coarse or even coarser
than the concentric ridges. Lucina semperiana, Issel, has more numerous and more
slender radiating riblets than the preceding species, and its concentric ridging is of a
stronger character than the riblets ; and finally, Lticina seminula, Gould (judging from a
specimen in the British Museum which had been compared with Gould's type), is
ornamented with still finer concentric ridges and less conspicuous cross costellee. All
three forms have very deep lunules, especially Lucina pisum, and a peculiarly raised-
posterior dorsal area.

Lucina ( Codahia) pisum, Reeve.

Ludna pisvm, Eeeve, Conch. Icon., vol. vi. pi. xi. figs. 66, a, h.
Lucina pisum, H. and A. Adams, Genera Eec. Moll., vol. ii. p. 467.

Habitat. — Station 188, south of New Guinea, in 28 fathoms (Challenger) ; Port
Essington (Jukes in Brit. Mus.); Singapore, in sandy mud, at a depth of 7 fathoms
(Cuming).

The radiating costiB in this species are only about eleven in number, very strong,
and crossed by about sixteen stout concentric ridges, which are somewhat nodose upon the
costse, and gradually attenuated at both ends, which are devoid of longitudinal ribs.
The lunule is small but remarkably deep, and wider than long. The inner edge of the
valves is very strongly dentate along the lower margin, and very minutely crenulated at
the posterior truncated side.

Lucina [Codahia) levukana, n. sp. (PL XIII. figs. 6-6a).

Testa minuta, mediocriter crassa, oblique ovata, in?equilateralis, alba, convexiuscula,
lunula profunda instructa, liris tenuibus concentricis, aliisque radiantibus in interstitiis
multo tenuioribus ornata. Margo dorsi anticus oblique excavatus, posticus rectiusculus,
declivis. Latus anticum latum, rotundatum, posticum angustius. Umbones mediocriter
producti, ad apicem incurvati, antice versi. Lunula profunda, margine elevato indistincto
circumdata. Dentes cardinales valvse sinistrse duo crassi, divergentes, subfequales ;
laterales validi, remoti. Margo valvarum internus minute denticulatus. Ligamentura
internum, angustum, in sulco profundo positum.

182 THE VOYAGE OF H.M.S. CHALLENGER.

Of this sj5ccies only two left valves are at present known. These, although of very-
small size, are ajiparently adult, judging from their thickness of structure, the denticulate
inner margin, and the strong character of the hinge. It is a species of an oblique ovate
or rounded growth, rather strong for so small a form, moderately convex, excavated in
the lunular region, and a little depressed down the posterior slope. It is white, somewhat
inequilateral, broadly rounded in front, narrower behind. The sculpture consists of
strongish, rather elevated concentric riblets somewhat narrower than the interstices
between them, which exhibit excessively fine radiating lirse. The beaks are rather large,
prominent, curved over towards the front, and not very acute. The lunule is deeply
depressed, somewhat indistinctly defined by a raised edge and sculptured by the fine
extremities of the concentric ridges. The left valve has two cardinal teeth and the right
probably the same number. They are strongish, about equal in size, and diverging.
The anterior is erect, beneath, or very slightly in front of, the tip of the umbo and free
from the dorsal edge, the posterior being directed backwards, and perhaps a trifle
slenderer. The lateral teeth are strongly developed, and about equidistant from the
beak. The ligament is totally internal, elongate, narrow, and placed in a deep groove
below the dorsal margin behind the posterior cardinal tooth. The inner edge of the
valves, with the exception of that portion occupied by the hinge and lateral teeth, is
minutely denticulated. The muscular scars are fairly well defined, the pallia! line simple,
and the inner surface of the valves dull, under the microscopic appearing rather rugose.

Length 2f mm., height 2^, diameter If.

Habitat. — Off Levuka, Fiji Islands, in 12 fathoms.

This is a remarkable little shell on account of its obliquity, the expanded anterior end,
the strong hinge, and denticulate margin of the valves. It differs in the last mentioned
character from Lucina quadrata, Angas, a species found at Port Jackson which has a
somewhat similar form and the same hinge-characters, but is diflferently sculptured
externally.

Lucina (Codakia) congenita, n. sp. (PI. XIII. figs. 7 -7a).

Testa Lucince levuhance similis, sed minus obliqua, liris concentricis validioribus,
radiantibus fortioribus, lunula breviori instructa, margine valvarum interuo crassiori,
donticulis majoribus munito.

This species bears considerable resemblance to Lucina levukana, but may be distin-
guished by its less oblique form, the anterior side being less produced and not so
expanded. The posterior side of the valves displays more of a depression, the lunule is
shorter, and consequently the front dorsal margin is more briefly excavated. The
umbones in this species are hardly so peaked, the concentric lirse a good deal thicker

REPORT ON THE LAMELLIBRANCHIATA. 183

and fewer in number, and the radiating sculpture is also of a coarser character. The
constitution of the hinge is very similar, but in Lucina levukana the anterior lateral
teeth are more remote from the cardinals than in this species. The edges of the valves of
the latter are considerably thickened, and the denticles on the inner margin are fewer and
stouter than in the Fijian funii.

Length 3| mm., height 3^, diameter 2^.

Habitat. — Station 185b, east of Cape York, North Australia, at a depth of 155
fathoms ; coral sand.

■Lucina (Codakia) hawaiiensis, n. sp. (PI. XIII. figs. 8-8a).

Testa ineequilateralis, oblongo-rotundata, paulo obliqua, ante umbones exeavata,
antice late curvata, postice angustior, alba, lamellis tenuibus jjarum elevatis costeUisque
crassioribus radiantibus minus elevatis cancellata. Margo dorsi anticus ^Jrimo excavatus,
leviter declivis, posticus brevior, magis obliquus, rectiusculus ; umbones parvi, leviter
prominentes, incurvati, antrorsum versi. Lunula parva, subprofunda, pellucida.
Dentes cardinales duo in valva sinistra, unicus in dextra validus, triangularis, medianus.
Laterales fortes, subsequidistantes, posticis paulo propius umbones positis. Ligamentum
externum, supra marginem locatum. Pagiua interna alba, cicatricibus magnis notata,
ad marginem denticulata.

A single specimen and an odd valve, which probably do not represent the adult state
of the species, are all that are at present known.

The shell is rather thin, having a semipellucid appearance, of an oblong irregularly
rounded form, fairly convex, rather inequilateral, and somewhat oblique. The posterior
dorsal margin is short, almost straight, and rather sloping, the anterior being longer, less
oblique, concave at first, and then rounding into the broadly curved anterior end, which is
wider than the hinder extremity. The beaks are small, smooth, opaque white, incurved
over the small deepish pellucid lunule. The sculpture consists of slender slightly elevated
concentric lamellae which pass over less raised but thicker radiating costellse. The hinge
is composed of two cardinal teeth in the left valve and one in the right, and a small
ligament placed in a narrow groove on the hinder dorsal edge in each valve. All the
cardinals are strongish, those in the left valve being divergent, and separated by a
triangular pit, which receives the strong central tooth of the right. The lateral teeth, too,
are thickish and well developed, and moderately remote from the centre of the hinge-
plate, the anterior being a little more distant than the posterior. The inner margin of
the valves is rather coarsely dentate, the muscular scars are large, and the pallial
impression is simple.

Length 3^ mm., height 2f, diameter 2^.

184 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat. — Dredged in 40 fivthoms among the reefs off Honolulu, Sandwich Islands.

In form this species is somewhat hke Lucina quadrata, Angas, but has a different
style of sculpture, the concentric ridges being further apart, the radiating lirse more
distinct, and the inner margin of the valves consequently denticulate. The hinge-
characters are the same in both.

Lucina (Codakia) Jijie7isis, n. sp. (PI. XIII. figs. 9-9a).

Testa paulo obliqua, irregulariter rotundata, mediocriter convexa, alba, ante urn bones
aliquanto excavata, postice subdepressa, liris tenuibus numerosis radiantibus aliisque
concentricis grracilioribus mag-is remotis cancellata. Dens cardinalis unicus in valva dextra
conicus, medianus ; posticus lateralis erectus, intra marginem situs, anticus nuUus.
Ligamentum internum obliquum, profunde infra marginem dorsalem posticum locatum.
Pagina interna hand nitida, punctulata, ad marginem subtLIiter denticulata. Cicatrices
magnse ; paUii sinus simplex.

This species is a little oblique, more or less rounded, moderately convex, white,
exhibiting a small luuular excavation and a slight depression down the posterior side at a
little distance from the margin. The sculpture consists of numerous very fine radiating
lirse, which are crossed by others stiU more slender and rather further apart. These
towards the hinder side are, except in the faint depression, a little lamelliform. The
umbones are smooth, moderately prominent, curved over towards the anterior side, and
not very acute. There is in the right valve a single conical erect cardinal tooth situated
just below the tip of the beak, having on each side a deepish pit which apparently
indicates the presence of two cardinals in the left valve, at present unknown. On the
posterior side there is a moderately elongate lateral tooth, sej)arated from the outer
margin by a deepish furrow. The ligament, which is internal, is deeply located in a long
narrow groove running obliquely from near the apex beneath the hinder dorsal Hne.
The inner surface of the valve is dull, without gloss, exhibiting a considerable number of
minute shallow punctures not arranged apparently in any particular order. The outer
margin is finely denticulated, the number of teeth being nearly one hundred. The
muscular scars are rather large and the palUal line simple.

Length 5^ mm., height 5, diameter 4.

Habitat. — Off Levuka, Fiji Islands, in 12 fathoms.

'Lucina (Codakia) sp. juv.

Habitat. — Amboina, in 15 to 20 fathoms.

As but a single valve, 2^ mm. in length, was obtained, which has the appearance of
being but the young state of some larger species, I refrain from naming it, although

REPORT ON THE LAMELLIBRANCHIATA. 185

apparently distinct from any known form. It is rather convex, rounded and concave in
front of the umbo, where there is a small deepish lunule. It is sculptured with about
fifteen flatly rounded radiating ribs, which arc al)sent down each side, and concentric
elevated lines of growth. There is a single cardinal tooth in this right valve, and a short,
erect, subequidistant lateral on each side ; the lower margin is rather strongly denticulated
where the ribs terminate, but smooth at the sides where the costae are wanting.

Lucina (Loripes) desiderata, n. sp. (PI. XIII. figs. 10-lOa).

Testa parva, tenuis, iufequilateralis, alta, postice radiatim impressa, antice profunda
lunulata, albida, concentrice tenuissime lirata, liris numerosis sublamelliformibus prope
lunulam et marginem dorsalem posticum cristatis. Margo dorsi anticus brevis, valde
excavatus, posticus longior, rectiusculus, vel parum convexus. Latus anticum regulariter
curvatum, posticum ad terminum impressiouis leviter sinuatum. Umbones parvi, acuti.
Lunula elongata, Isevis, conspicue excavata, areaque postica, angusta, Isevis, valde impressa.

This little species is higher than long, somewdiat inequilateral, moderately convex,
thin, white, and marked with a shallow radiating dej^rcssion down the posterior side,
producing a faint indentation or sinuation in the outline, which, along the lower portion
and in front, is regularly circularly curved. The sculptures consists of numerous very
fine thin concentric lirse, which, especially towards the ventral margin, become some-
what lamelliform, and towards the lunule and hinder dorsal slope are elevated into
small, thin, dentiform projections. The lunule is rather large, smooth, and very deep,
and defined by sharp edges. The area is long, narrow, also deepish and circumscribed
by acute margins. The beaks are small, sharp, well -curved over the lunule, and consider-
ably in front of the middle. The left valve has two small divergent cardinal teeth,
separated by a triangular pit, which receives a corresponding tooth in the right valve.
The internal ligament is in a deepish groove just within the dorsal margin behind the
teeth. The inner surface, owing to the thinness and semitransparency of the valves,
exhibits the concentric ornamentation of the exterior, and towards the lower part is
somewhat indistinctly radiately substriated.

Length 3^ mm., height 3f, diameter 2^.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

This is a small species, resembling in its radiating depression some of the typical
forms of Cryptodon.

Lvcina (Loripes?) jacksoniensis, n. sp. (PI. XIII. figs. 11-116).

Testa globosa, rotundata, tenuis, subsec^uilateralis, albida vel dilute fusco tincta,
incrementi lineis confertis striisque numerosis tenuissimis sculpta. Lunula parva, baud

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 24

186 THE VOYAGE OF H.M.S. CHALLENGER.

profunda, lanceolata. • Umbones parvi, nivei, paulo prominentes, antrorsum versi.
Cardo dente unico conico iiifni apicem in valva dextra et 'duobus in sinistra instructa, et
margo posticus dorsalis valvas dextr^e dente laterali elongato, baud couspicuo munitus.
Ligamentum internum magnum, obliquum, in sulco infra marginem locatum. Pagina
interna baud nitida, subrugose radiatim striata, margine exteriori minute crenulato.

Tbis species is tbin, ratber globose, about equiLateral, rounded, wbitisb, and,
judging from tbe single specimen under examination, somewbat tinted near tbe central
portion of tbe valves witb pale brown. It is sligbtly glossy, and sculptured witb fine
concentric lines of growtb and equally fine radiating strise, wbicb are almost obsolete
down eacb side and more or less indistinct near tbe middle of tbe valves, and entirely
absent near tbe umbones. Tbe anterior dorsal margin is oblique, and a little concave
by reason of tbe small, sbortly lanceolate and sligbtly sunken lunule. The beaks are
small, smootb, wbite, only a very little elevated, and curve over towards tbe front.
Tbe binge is composed of a single cardinal tooth in the right valve wbicb fits in between
two in the left, of which tbe anterior is tbe larger, and a narrow insignificant lateral in
tbe right, near but distinct from the posterior dorsal edge, which is received by a
corresponding groove in the other valve. Tbe ligament is rather large, entirely internal,
and placed in an oblique furrow, extending from the apex not c|uite to the end of tbe
lateral teeth. The interior has very little gloss, and is rather strongly radiately striated
and marked with numerous shallow punctures, neither being met with beyond the
pallial line. The muscular scars are large, and the inner margin of tbe valves minutely
crenulated.

Length 9^ mm., height 9, diameter 6f.

Habitat. — Port Jackson, New South Wales, in 6 to 1 5 fathoms.

This species is larger than Lucina parvula, Gould, also found at this locality,
more finely radiately sculptured, and has the inner edge of the valves more delicately
notched.

Lucina [Loripes?) gordoni, n. sp. (PI. XIII. figs. 12-1 2a).

Testa j)arva, modice convexa, rotundata, sequilateralis, alba, lineis increment!
tenuibus elevatus striisque radiantibus obsoletis sculpta : margo dorsi anticus leviter
obliquus, parum excavatus, posticus rectiusculus, horizontalis. Latus anticum regu-
lariter arcuatum, posticum obtusius. Umbones parvi, acuti, paulo prominentes.
Dentes cardinis in valva sinistra duo divergentes insequales, antico majori ; margo
posticus dente laterali parvo instructus. Ligamentum internum angustum, in sulco
profundo obbquo situm. Pagina interna baud nitida, plus minusve radiatim substriata,
margine minute crenulato circumdata.

REPORT ON THE LAMELLIBRANCHIATA. 187

Of this species only a siugle left valve is at present knowu. It is roundish, white,
about equilateral, moderately convex, not very solid, and sculptured with fine elevated
concentric lines (which are scarcely large enough to be termed lamellse) crossed by
numerous not very apparent radiating substrise. There is a slight narrow lunular
depression, causing the anterior dorsal slope to be faintly concave. The hinder margin
is short, straight, and hardly at all oblique, rounding off somewhat squarely into the
side margin, which is more obtuse and less curved than the anterior side. The umbo
is small, peaked, curves over towards the front, and rises a little above the hinge-line.
In this valve there are two distinct, divergent, cardinal teeth, which are unequal in size,
the front one being more than double the size of the other, and obliquely sloping
towards the anterior end. There is a not very strongly developed posterior lateral
tooth, separated from the outer margin by a shallow groove, which, no doubt, receives
a corresponding tooth in the other valve. The ligament is totally internal and situated
in a deep, narrow, oblique furrow, beneath the hinder dorsal mai'gin. The interior is
dull, with the exception of that portion of the surface outside the pallial line which is
glossy. Towards the middle there are traces of radiating strias, and the outer edge is
very finely denticulated.

Length 5 mm., height 4^, probable diameter of the complete shell 2f.

Habitat. — Off Levuka, Fiji Islands, in 12 fathoms.

This species closely resembles Luclna jacksoniensis, but is less distinctly radiately
striated.

Cryptodon, Turton.

This genus was founded in 1822 by Turton^ for the reception of the Tellina
Jlexuosa of Montagu. It is considered by some authors identical with Axinus of
Sowerby. If this really be the case the latter name should be adopted, as it was
published a year before Cryptodon. It appeared in the fourth volume of the Mineral
Conchology, which bears on the title-page the date 1823. This, however, only refers to
the completed volume, for this work was published in parts, and that containing
plate 315, on wdiich the type {Axinus angulatus) is figured, was issued in 1821. Both
Agassiz' and Herrmannsen^ quote the date of the volume as that of the publication
of this genus, and no doubt this has misled Messrs. Adams and Chenu into adopting
the name proposed by Turton.

As far as I can ascertain, the hinge of Axinus angulatus has never been described,
for the shell associated with it by Nyst * seems to me distinct.

Such being the case, I prefer employing the name Cryptodon, foi-, although

1 Conch. Inst. Brit. Dithyra, p. 121. ^ Nomen. Zool., Index universalis, p. 42, Mollusca, p. 10.

^ Indicia geu. nialacol. prim., vol. i. p. lt)(). ^ Coq. et Polyp, foss. terr. tert. Belj^ique, p. 140.

188 THE VOYAGE OF H.M.S. CHALLENGER.

externally Axinus angulatus appears congeneric, it is possible that the hinge may be
differently constructed.

Cryptodon watsoni, n. sp. (PI. XIV. figs. 1-la).

Testa tenuis, paulo insequilateralis, anguste lunulata, mediocriter globosa, rotundata,
superne lata, subquadrata, alba, incrementi lineis tenuibus (hie illic fortioribus) striata,
striis minutis radiantibus irregularibus sculpta. Margo dorsi anticus parum declivis,
leviter concavus, posticus rectiusculus, fere horizontalis. Latus anticum aliquanto
augustatum, obtuse subnasutum, posticum multo altius, late curvatus. Margo ventris
regulariter curvatus, antice oblique ascendens. Umbones parvi, mediocriter acuti,
paulo antemediani, parum supra marginem producti. Cardo edentulus. Ligamentum
elongatum, angustum, in sulco pone umbones intra marginem positum. Pagina interna
radiatim substriata, antice lineis elevatis paucis radiatim curvantibus instructa.
Cicatrices intequales, postica subpyriformi, antica irregulari, obliqua, partim intra
lineam pallii producta.

This species is white, moderately convex, rather thin, broad above, somewhat
shouldered on both sides, curved beneath. It is much higher behind than in front,
where, through the upcurving of the ventral margin, it has a faintly nasute appearance.
The valves are slightly inequilateral, the beaks, which are small, only a little elevated
above the dorsal line and not very acute, being situated somewhat in advance of the
middle. They also present a narrow lunule which is elevated along the centre, then
somewhat depressed. The sculpture consists of fine concentric lines of growth, some of
which, at intervals, are more conspicuous than the rest, as if marking periodical cessation
(^f orowth. In addition the surface exhibits a fine but rather irregular radiate striation.
The front dorsal margin is very slightly concave and a trifle oblique. The posterior is
almost rectilinear and nearly horizontal. The ventral outline is regularly curved
and much ascending anteriorly. The hinge is toothless and the ligament must be
only partially visible externally, being contained in a narrow groove within the hinder
dorsal margin, of which it occupies rather more than half the length. The inner surface
of the valves is not particularly glossy, radiately substriate, and marked in front
with one or two slender elevated lines curving; from the beaks to the anterior muscular
scar. This is of an irregular elongate form, almost parallel with the ventral margin,
and falls partly within the simple pallial line. The hinder scar is perhaps a trifle larger
and somewhat pear-shaped.

Length 20 mm., height 17^, diameter 11.

Habitat. — Station 219, off the north of the Admiralty Islands, at a depth of
150 fathoms; coral mud.

REPORT ON THE LAMELLIBRANCHIATA. 189

This is a less convex species thau Lucina hulhda, rather longer, more pouting in
front, more equilateral, and has a much longer lunule. The radiating sculpture also is
more distinct, the ligamental groove broader, and the anterior muscular scar twice or
three times as broad.

Cryptodon hullulus (Eeeve).

Lucina bullula, Eeeve, Conch. Icon., vol. vi. fig. 35.

Habitat. — Amboina, in 15 to 20 fathoms (Challenger) ; Port Essington (J. B. Jukes
in Brit. Mus.).

The distribution of this species has not been previously recorded. The figure in
the Conchologia Iconica does not represent the adult form of it, for in the British
Museum there is a specimen from Port Essington which is 17 mm. long, 15 high, and
12 in diameter, and the single left valve from Amboina is even a little larger.

This is a very thin species, slightly lunuled, considerably convex, rather shouldered
above and prominently curved along the lower margin. It is sculptured with fine lines
of growth and indistinct traces of radiating substria;. The toothless hinge-line is very
thin, and consequently the longish ligamental groove is very narrow. The anterior
muscular impression is remarkably narrow, and descends obliquely within the pallial line.

Cryptodon moseleyi, n. sp. (PI. XIV. figs. 2-2a).

Testa tenuissima, ovata, valde iua;quilateralis, mediocriter convcxa, semipellucido-
alba, haud nitida, incrementi lineis tenuibus striata, epidermide tenui pallide olivacea
prope marginem induta. Marge dorsi ante umbones elevatus, arcuatus, postice obliquus,
rectiusculus. Margo ventralis paulo curvatus, latum posticum versus obhque ascendens.
Umbones parvi, vix supra marginem producti, post medium siti. Cardo edentulus.
Ligamentum internum obliquum, pone apicem locatum. Pagina interna subuitens,
plus minusve radiatim substriata.

This is an excessively fragile shell, broadly ovate, very inequilateral, the anterior
side being both longer and broader. It is moderately convex, of a dirty white colour,
not glossy on the surface, and clothed to some extent with a very thin pale olive
epidermis, especially towards the dorsal margin. The sculpture consists of fine Lines of
growth, some here and there being rather more conspicuous than the rest. The front
dorsal margin is arched and higher than the beaks, the posterior, on the contrary, being
shorter, straightish, and obliquely sloping. The anterior end is regularly semicircularly
curved, the posterior rather more obtusely arcuate, and the curve of the ventral margin
gentle and slowly ascending Ijehind. The umbones are small, scarcely elevated above

190 THE VOYAGE OF H.M.S. CHALLENGER.

the hinge-line, slightly eroded at the tip, and situated at about three-eighths of the
entire length from the hinder extremity. The hinge-plate is absolutely toothless, and
only very slightly thickened on both sides. The internal ligament is small, yellow,
and, starting from beneath the tip of the beaks, extends about a millimetre backwards.
The interior of the valves is moderately shining, feebly substriated in a radiating
direction, and, under the microscope, appears to be minutely rugose. The muscular
scars and pallial impression are too indistinct for description.

Length 16 mm., height 12, diameter 6.

Habitat. — Station 133, South Atlantic, in 1900 fathoms; Globigerina ooze.

This shell is unusually thin for a Lucinid, and the hinge is very delicate, as might
be expected in one from such a great depth.

? CryiDtodon barhatus (Reeve).

Lndiia hatiiata, Eeeve, Conch. Icon., vol. vi. pi. iv. figs. 16, a, h.
Habitat. — Station 33, off Bermuda, in 435 fathoms ; coral mud.

A single left valve, all that was obtained, agrees exactly with this species in form,
the toothless character of the hinge, the position of the ligament, the form of the
muscular scars, and in the small deep lunule. The external concentric lines of gro\\i;h
are, however, rougher to the touch and apparently more raised, and the shallow
depression down the posterior side is a little nearer the dorsal margin.

Cryptodon falklandicus, n. sp. (PL XIV. figs. 3-3«).

Testa rotundata, mediocriter convexa, paulo iutequilateralis, alba, cretacea, epidermide
tenui flavescente induta, concentrice striata. Valvse tenues, sulco postico lato radianti
haud profundo arataj. Margo ligamenti leviter arcuatus, anticus declivis, rectiusculus.
Latus anticum ad extremitatem rotundatim subangulatum, posticum breviter truncatum.
Pagina interna alba, parum nitida, plus minusve rugosa. Cicatrix antica. magna,
elongata, irregularis, posterior minor, brevior.

This species is a trifle longer than high, roundish, moderately convex, thin, white, of
a chalky appearance, and covered more or less with a thin yellowish epidermis. It is
somewhat inequilateral, the beaks being situated a little in advance of the centre, and
striated rather roughly by the lines of growth. The valves exhibit a broadish shallow
depression down the posterior side, which produces a short truncated extremity to the
margin. There is also a faint depression ou the opposite side, marking off an elongate
cordate lunular space. The posterior or bgamental portion of the dorsal margin is a
little curved and less oblique than the anterior, which is straightish, and joins the upcurv-
ing ventral outline almost in a rounded angle. The hinge-line is thickened slightly to

EEPORT ON THE LAMELLIBEANCHIATA. 191

support the strongisli ligament, also just in front of the apices. The interior of the
valves is opaque-white, hardly at all glossy, and rather rough through being somewhat
punctate iind irregularly striate. The anterior muscular impression is very long, with a
jagged outline, and falls partly within the subpunctate pallial line. The hinder scar is
much smaller, and somewhat coarsely striated.

Length 15^ mm., height 14|, diameter 8.

Habitat. — Station 316, off the Falkland Islands, in 3 to 5 fathoms ; mud.

Lucina phcifera (A. Adams), from Borneo, is somewhat like this species in form,
having a radiating depression dowTi each side, but is more strongly concentrically ridged,
and has a single anterior lateral tooth in each valve, whilst Cryptodon falklandicus is
totally edentate.

Cryptodon rufolineatus, n. sp. (PL XIV. figs. 4-4o).

Testa insequilateralis, modice convexa, rotundata, albida, apices versus dilute rufescens,
lineis pallide rufis paucis radiata, subleevigata, striis incrementi tenuibus sculpta, antics
infra umbones sublunulata. Pagina interna dilute rufescens, haud nitida, radiatim
substriata. Cardo tuberculo parvo in utraque valva instructus ; ligamentum angustum,
parvnm, in sulco infra marginem dorsalem situm.

This is a roundish species, but rather longer than high, and narrower and more
pointed in front than behind. It is moderately globose, somewhat inequilateral and
glossy, whitish, marked at intervals with narrow subpellucid zones, reddish towards the
umbones, and ornamented with a few pale red rays. The front dorsal margin is fainlly
concave and sloping, the posterior being longer, nearly straight, and less oblique.
There is a slight lunular depression, which is not, however, clearly circumscribed. The
hinge is almost toothless, there being only a small tubercular prominence beneath
the beak, probably in both valves, although I have but a single left valve from which
to judge. The ligament is totally internal, small, and located in a narrow groove
under the posterior dorsal edge. The interior of the valves is not glossy, except
near the outer flatfish margin. It is faintly tinged with red near the central part, and
exhibits, in a slight degree, the external rays, and is radiately substriated. The front
muscular scar is rather large, and, as usual, falls within the ^Jallial line.

Length 6 mm., height 5, supposed diameter of the perfect specimen 3.

Habitat. — Ofi'Levuka, Fiji, in 12 fathoms.

This is a pretty little species, judging fi'om the single valve at hand, which, how-
ever, is probably not full grown, and remarkable for being rayed with colour, a very
unusual feature in shells belonging to the Lucinidse.

192 THE VOYAGE OF H.M.S. CHALLENGER.

Cryptodon luzonicus, u. sp. (PI. XIV. figs. 5-5a).

Testa parva, tenuis, insequilateralis, globosa, obliqua, rotuude subquadrata, alba,
epidermide tenuissima lutescente induta, concentrice subdistanter graciliter lirata. Um-
bones nivei, nitidi, promiueutes, incurvati, antrorsum involuti. Cardo fere edentulus,
valva dextra tuberculo miuuto dentiformi sub apicem instructa. Pagina interna nitida,
radiatim tenuissime striata, margine simplice circumdata.

This species is very thin and fragile, rather convex, and of an oblique growth, the
anterior side being produced so as to give the shell an inequilateral aspect. The outline
is roundish -square, but interrupted above by the prominent umbones. The front side is
higher and less curved than the posterior, and the dorsal line on the anterior side is
longer and not so sloping as the hinder margin. The shell is pure white, but clothed to
a great extent with a thin yellowish slightly fibrous epidermis. It is sculptured with
numerous fine concentric lirse, which are not nearly so broad as the interstices between
them, and gradually become obsolete upon the smooth snow-white beaks, which are rather
prominent, glossy, well curved over towards the front, the apices, however, having about
a central position on the dorsal line. In addition to the liras, the entire surface of the
valves has the appearance, under a strong lens, of being minutely dotted all over with
small pellucid spots. The hinge is almost entirely destitute of teeth, there being only a
very small tubercle on the hinge-line of the right valve immediately under the tip of the
beak. The ligament is placed on the hinge-line between the valves, so that it is partly
external and partly concealed. The interior of the valves is glossy hwt very finely
striated in a radiate direction, and the outer margin is simple and smooth. The scars
and paUial line are indistinct.

Length 6^ mm., height 6^, diameter 5.

JZ^at/tof.— Station 205, ofi" the west coast of the Island of Luzon, Philippines, in 1050
fathoms ; blue mud.

Cryptodon jlexuosus (Montagu).

Tellina flexuosa, Montagu, Test. Brit., p. 72.

Ludna flcxuosa. Reeve, Conch. Icon., vol. vi. pi. xi. fig. 62.

Lucitia flexuosa, Forbes and Hanley, Brit. Moll., vol. ii. p. 54, pi. xxxv. fig. 4.

Axinus flexuoMis, Jeffreys, Brit. Conch., vol. ii. p. 247, and vol. v. p. 179, pi. xxxiii. fig. 1.

Axinus flexuosiis, Jeffreys, Proc. Zool. Soc. Loud., 1881, p. 701.

Axmus fli'xuosus, G. 0. Sars, Moll. Reg. Arct. Norv., p. 59, pi. xix. figs. 4, a, h.

Cryptodon flexuoms, Turton, Conch. Dithyra, p. 121, pi. vii. figs. 9, 10.

Habitat. — Station 75, of Fayal, Azores, in 450 fathoms ; volcanic mud.

Only a single valve which undoubtedly belongs to this species was dredged. It
belongs to the variety named polygona.

For the distribution of this species, see Dr. Gwyn JeS"reys' paper. ^

1 Proc. Zool. Soc. Land., 1881.

REPORT ON THE LAMELLIBRANCHIATA. 193

Cryptodon croulinensis (Jeffreys).

Clausina cwidinensis, Jeffreys, Ann. and Mag. Nat. Hist., 1847, vol. xx. p. 19 ; op. cit., 18.58,

vol. ii. p. 122, pL V. figs. 2, a-c.
Axinus croulinensis, Jeifreys, Brit. Conch., vol. ii. p. 2.50, vol. v. p. 180, \)\. xxxiii. lig. 2.
Axinus croidinetisis, Jeffreys, Proc. Zool. Soc. Lond., 1881, p. 703.
Axinus croulinensis, G. 0. Sars, Moll. Reg. Arct. Norv., p. 62, pi. xix. fig. 8.

Habitat. — Station VIII., off Canary Islands, in 620 fathoms ; Station 33, off
Bermuda, in 435 fathoms ; and Station 78, off the Azores, in 1000 fathoms.

A single specimen from the first locality, one valve only from the second, and about
a dozen valves from Station 33, is all that was obtained. That from the Canary
Islands and the Bermudan valves are hardly so obliquely expanded in front as examples
from the Shetland Islands with which I have compared it, and the posterior impressed
rays are so much stronger that I feel doubtful whether they may not be specifically
distinct.

This species has been found at the island of Skye, the Shetlands, in deep water in
the Atlantic, off the Norwegian coast, in the Mediterranean and the Adriatic. Also
found fossil in PUocene and Post-tertiary formations (teste Jeffreys).

Cryptodon incrassatus, (Jeffreys), var.

Axinus incrassatus, Jeifreys, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 492.
Axinus incrassatus, Jeffreys, Proc. Zool. Soc. Lond., 1881, p. 703, pi. Ixi. fig. 7.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

The few odd valves from the above locality have already been referred to this species
by Dr. Gwyn Jeffreys in the Proceedings of the Zoological Society. Not having had an
opportunity of comparing them with typical examples, I cannot give any positive
opinion respecting their identity. Judging, however, from the description in the
Annals and the figure in the Proceedings, I feel no hesitation in pronouncing them a
well-marked variety, and am almost inclined to hold them specifically distinct. They are
rounder and less oblique in form, and consequently more equilateral. The hinge-plate
cannot be described as " remarkably thick on both sides," the posterior side in the right
valve is not crenulated, nor does the anterior side correspond with the figure. There is
but one right valve in the collection, and in this the hinge-line is produced immediately
beneath the beak, the minute projection (it can scarcely be termed a tooth) fitting in
under the tip of the umbo in the other valve. The front portion of the hinge-plate in
this valve is thin, whilst in the left it is a little thickened. The posterior dorsal line in

(zool. chall. EXP. — PART XXXV.— 1885.) Mm 25

194 THE VOYAGE OF H.M.S. CHALLENGER.

the right valve is slender at first, then becomes broader below the first angle, or, in other
words, along the truncation, with a narrow groove along the middle which receives the
acute edge of the left valve. In the latter the margin is most expanded at the upper
angle. There does not appear to be any trace of a ligamental groove.

Cryptodon sp.

Habitat. — Station 344, oif Ascension Island, South Atlantic, in 420 fathoms;
volcanic sand.

As but a single minute valve, only about a millimetre in length, was obtained, 1
refrain from giving more than a mere record of its discovery. It doubtless is the
young state of a probably new form approaching Cryjitodon ci'oulinensis, but rather less
oblique, rounder, and not so peaked at the imibones.

Cryptodon marionensis, u. sp. (PL XIV. figs. 6— 6cf).

Testa parva, teuuissima, alliida, subpellucida, irregulariter rotundata, mediocriter
convexa. Valvse impressionibus duabus radiantibus baud profuudis postice notatae,
incrementi lineis striatse, sculptura peculiari quasi microscopice subpunctata undique
ornatse. Margo dorsi ante umbones ieviter concavus, posticus vix convexus. Latus
anticum rotundatum, posticum baud profunde bisinuatum. Umbones parvi, acuti,
mediani, antrorsum versi. Cardo edentulus, sed linea cardinis in valva sinistra infra
apicem paulo incrassata et producta. Ligamentum omnino internum, in sulco angusto
infra marginem dorsalem situm.

Length 4 mm., height 4^, diameter 3.

Habitat. — Prince Edward and Marion Islands, in 100 to 150 fathoms.

This species is the southern form of Cryptodon gouldii, Philippi, and Cryptodon
jlexuosus, Montagu, both of which species it closely resembles. It is, however, flatter,
and perhaps a trifle longer than either, and the lower of the two furrows, or rather
depressions, down the hinder side of the valves is rather broader and certainly not so
deep as in Cryptodon Jlexuosus. The ligament also in the present species appears to
be set in a somewhat deeper groove, and the prominence of the hinge-line beneath the
umbo in the left valve is more marked than in either of the two species referred to.
If these differences, slight as they are, prove constant, I think it right they should be
held of specific imjjortance.

REPORT ON THE LAMELLIBRANCHTATA. 195

Cryptodon sp.

Habitat. — Station 23, off Sombrero Island, West Indies, in 450 fathoms.

A single right valve of a small species was dredged at this locality, which appears
to be distinct from any j^reviously described. It is somewhat like Cryptodon croulin-
ensis in size and form, but does not exhibit any depression down the posterior side.

Family Ungulinid^.

Diplodonta, Bronn.
Diplodonta subgranulosa , n. sp. (PI. XIV. figs. 7-7a).

Testa subinflata, insequilateralis, alba, antice angustata, acute rotundata, postice longe
latior, concentrice leviter striata, ubique minute rugosa vel subgranulata. Umbones
parvi, acuti, leviter involuti. Margo dorsi posticus subhorizontalis, rectiusculus, anticus
valde obliquus, levissime curvatus. Margo ventris arcuatus, antice multum adscendens.
Margo dorsalis antice breviter, baud profundeque intus sulcatus. Dens cardinis duplex
valvse sinistrse infra umbonem situs, profunde fissus, valde erectus ; dens posticus tenuis,
lamellaris, obliquissimus. Ligamenti fossa intra marginem locata.

This species is rather convex, considerably inequilateral, much narrower in front than
behind, white, not glossy, exhibiting fine concentric lines of growth, and sculptured
throughout with a very fine subgranulation. The dorsal outline is scarcely curved on
either side, the hinder portion being horizontal and the anterior part very oblique. The
front extremity is sharply rounded, whilst the opposite side is much more broadly
curved, forming at the upper part an obtusely rounded shoulder. The umbones are
small, but very little raised above the hinge-line, acute, somewhat incurved and directed
forwards. The hinge-plate beneath the beaks is broadish, so that the teeth do not pro-
ject beyond it. The double one in the left valve is thick, prominent, triangular, deeply
cleft at the top, and falls perpendicularly immediately beneath the apex of the beak. The
posterior tooth is very slender and oblique, and the ligamental groove is within the
outer margin, so that scarcely any portion of the ligament itself would be visible
exteriorly. Besides this groove the hinder margin exhibits only the faintest furrow, but
the anterior side is more distinctly sulcate, the groove, however, being short and
shallow.

Length 5f mm., height 4f, diameter 3^.

Habitat. — Station 208, Philippine Islands, in 18 fathoms ; blue mud.

The form and the surface, which has a minutely shagreened appearance, are the
characteristics of this species.

196 THE VOYAGE OF H.M.S. CHALLENGEI!.

Diplodonta scalpta, n. sp. (PI. XIV. figs. 8-8a).

Testa subcompressa, alba, subpellucida, insequilateralis, concentrice exillissime striata,
lineis elevatis subdistantibus opacis coneinne ornata. Umbones parvi, parum promin-
eutes, in f longitudinis positi, paulo prominuli. Mai'go dorsi utrinque rectiusculus,
antice intus anguste prelougateque sulcatus, oblique desceudeus, postice magis
horizontalis. Latus posticum altum, late arcuatum, superne indistincte subangulatum,
anticum acutius rotundatum. Ventris margo late curvatus. Cardo angustus. Dens
duplex profunde fissus, intus projectus. Ligamenti sulcus parvus, angustus, supra
marginem situs.

This species has a rather compressed shell. It is thin, semitransparent white, finely
striated with the lines of growth, and ornamented at intervals with thread-like white
ridges or lirse which, under a lens of low power, have the appearance of concentric scratches.
It is somewhat inequilateral, and a little longer than high. The hinder dorsal outline is
somewhat oblique and almost rectilinear, the anterior being equally straight, but more
sloping. The lower margin is broadly arcuate, and ascends rather more anteriorly than
behind. The posterior end is broader or higher, and more gently curved than the front,
and at the upper part forms an indistinct obtuse angle with the dorsal margin. The
umbones are very small, acute, a trifle antemedian, and only a little elevated above the
hinge-plate. This is narrow, and but slightly developed on either side of the cardinal
teeth. Of these the double triangular one is remarkable, is deeply slit at the top and
projects within the valve beyond the hinge-plate. The other tooth in both valves is
narrow, divergent, and not united at the upper extremity to the larger tooth. The
anterior dorsal margin has a shallow groove within in both valves, which is peculiar as it
reaches to the middle of the lateral outline. The hinder margin is not grooved, but only
has a furrow upon the border for the reception of the ligament, which may be described
as subexternal. The muscular impressions are scai'cely observable, and too indistinct for
description.

Length 7 mm., height G^, diameter 3^.

Habitat. — Station 187, off Cape York, North Australia, in 6 fathoms ; coral mud.

Its compressed form, the prolonged shallow groove within the front dorsal and
lateral margins, and the very deeply- fissured tooth projecting within beyond the hinge-
plate, are the most prominent features distinguishing this species,

Diplodonta corpulenta, n. sp. (PL XIV. figs. 9-9a).

Testa parva, globosa, tenuis, rotundata, subdiaphana, vix inasquilateralis, concentrice
tenuiter striata et subdistanter gracillime sublirata. Umbones minuti, parum prominentes,
paulo ante medium coUocati. Margo dorsalis antice curvatus, sul^horizontalis, postice

HEPORT ON THE LAMELLIBRANCHIATA. 197

oliliqiie le\'iterque arcuatus ; ventris margo aliquanto late arcuatus. Latus anticum
altuni, obtusum, posticum paulo acutius rotundatum. Dentos cardinis in valva sinistra
normales, antico bifido, crasso, postico gracili, elongate. Margo dorsi ante umbonem
iutus profunde efFossus, supra dentem bifidum levissime emarginatus vol depressus.
Ligamenti sulcus baud profundus, marginalis, angustus. Impressiones musculorum
magnag, elongatse.

The shell of this small species is thin, rather globose, rounded, a little longer than
high, concentrically finely striated, and exhibits at short distances minute elevated ridges
or lirse. It is white, slightly glossy, and inequilateral, the anterior side being a trifli'
shorter than the posterior. The front dorsal mai'gin is very slightly concave near the
beaks, then somewhat excurved, rising a little befoi'e commencing the descent to the side.
The hinder margin is feebly arcuate, and slopes more obliquely than the anterior. The
ventral outline is broadly curved, and forms with the dorsal margin a sharper curve
behind than in front. The umbones are very small, only a very little elevated above
the hinge-plate, not very acute at the tip, and are situated a trifle in advance of the
centre. In the left valve the front tooth is stout, strongly grooved at the top, falls
immediately beneath, the tip of the beak, and inclines but very slightly towards the front.
The hind tooth is very slender and oblique, elongate, and is almost connected with the
anterior tooth at the upper end, and at the lower extremity runs into the inner edge of
the hinge-plate, being separated from the other tooth by a deep triangular pit. The
anterior half of the hinge-plate is just a trifle broader than the posterior, remarkablj'
deeply and widely grooved. The hinder portion is also deeply channelled, a narrow
elongate slip behind the umbo being partitioned ofi" for the ligament, which would
scarcely be visible externally. The muscular scars are elongate and very large.

Length 4^ mm., height 4^^, diameter 3.

Habitat. — Station 187, west of Cape York, North Australia, in 6 fathoms; also
Station 188, a little farther west of Cape York, at a depth of 28 fathoms.

This species is distinguished from Diplodonta suhglobosa by its more ventricose form.
The anterior end is higher and more obtuse than the posterior, whilst in the other species,
on the contrary, the latter extremity is the more broadly arcuate. The hinge-plate, too,
in the present species is broader and more deeply grooved, the posterior tooth in the
left valve is longer and more oblique, the ligamental furrow is narrower, and the double
tooth is not so deeply bipartite as in the following species.

Diplodonta suhglobosa, n. sp. (PI. XIV. figs. 10-lOa).

Testa parva, rotundata, subglobosa, tenuis, baud nitida, striis concentricis tenuis-
simis sculpta, semipellucido-alba, paululum insequilateralis. Umbones parvi, parum

198 THE VOYAGE OF H.M.S. CHALLENGIER.

prominuli, aliquanto ante medium siti. Margo dorsi anticus leviter obliquus, subarcuatus,
posticus minus descendens, curvatus. Latus anticum postico angustius, arcuatum.
Margo ventris late curvatus, utrinque subsequaliter adscendens. Dentes cardinis inaequales
divergentes, antico valvse sinistra;, et postico in dextra crassis, insigniter bifidis. Margo
anticus intus sulco elongato baud profundo exaratus. Fossa ligamenti elongata, intra
marginem coUocata.

This species does not probably attain large dimensions. It is a little longer than
high, rounded, slightly inequilateral, the posterior side being a trifle the longer. It is
thin, semitransparent, not glossy, colourless and finely concentrically striated, the striae,
however, under a compound microscope appearing rugose or even granulose. The
dorsal outline is curved on both sides, and does not slope much. The obliquity is a trifle
greater anteriorly than behind, where the arcuation is a little more pronounced than in
front. The posterior end is certainly higher than the anterior, not much curved, and
shouldered or obtusely and indistinctly angled where it runs into the dorsal margin. The
lower outline is broadly arcuate, and ascends almost equally at each extremity. The
umbones are small, a trifle antemedian, and only a little elevated above the niargin. In
the right valve the hinder tooth and in the left the anterior are twice as stout as the
others and very deeply bifid, the former sloj)ing towards the posterior end and the latter
towards the front. The anterior dorsal margin in both valves is grooved within, the
furrow being rather long and shallow, and commencing at the front tooth extends about
half-way to the middle of the anterior end. In the right valve the dorsal outline, just
over the front slender tooth, is faintlj^ emarginate or feebly notched, or, in other words,
slightly pressed over towards the tooth. The groove for the ligament is within the outer
edge, elongate, rather broad and deep, so that little, if any, of the ligament would be
visible exteriorly. The muscular scars are indistinct, but appear to be elongate and
moderately large.

Length 4|^ mm., height 4, diameter 2f.

Habitat. — Station 187, near Cape York, North Australia, at a depth of 6 fathoms;
also Flinders Passage, in 7 fathoms.

Diplodonta consjncua, n. sp. (PI. XIV. figs. 11-lla).

Testa trigono-rotundata, alba, tenuis, subsequilateralis, concentrice exilissime striata.
Margo dorsi antice arcuatus, j^ostice vix longior, sequaliter curvatus, utrinque subsequaliter
obliquus. Margo ventris late arcuatus, ad utrumque latus paulo adscendens, in
dorsalem acute-rotundatim ambiens. Umbones parvi, acuti, aliquanto ante medium siti,
parum prominuli. Dens anticus valvae dextrse parvus, obliquus, posticus crassus,
triangularis, conspicue in medio fissus, in valva sinistra parvus, gi'acUis, antico magno

REPORT ON THE LAMELLIBRANCHIATA. 199

bifido. Ligamonti fossa elongata, pone dentem posticum locata. Margo valvarum
internus denticulis parvis insignibus circiter quinque antice instructus, postice acutus,
inferne anguste complanatus. Cicatrices musculares magate, elongatae. Pallii impressio
baud siuuata.

This small species is a little longer than high, subtriangularly rounded, a trirti'
inequilateral, thin, not very glossy, moderately gibbous, semitransparent-white, finely
sculptured with the concentric lines of growth. The umbones are minute, acute, pro-
duced only a little above the dorsal line, are scarcely incurved, and situated a trifle in
front of the centre. The dorsal margin is considerably curved on both sides and
descends a long way, forming with the broadly arcuate ventral edge sharply rounded
extremities. The hinge-plate is not very strong, and furnished in each valve with two
cardinal teeth, of which the hinder in the right valve and the anterior in the left are
twice as strong as the others, and conspicuously bifid. These teeth are divergent, the
anterior being directed towards the front and the posterior backwards. Behind the
latter comes the internal ligament which rests in a narrow oblique groove separated
from the tooth by an acute ridge. The inner edge of the valves is remarkable on account
of five or six distinct denticles situated about the middle of the front side. The lower
part especially towards the anterior end is narrowly flattened, whilst along the hinder
dorsal slope the margin is more acute. The muscular scars are long and large, and the
pallial line is simple.

Length 4 mm., height 3f , diameter 2^.

Habitat. — Station 187, depth 6 fathoms, coral mud; also Station 188, depth 28
fathoms, green mud ; also Flinders Passage, at a depth of 7 fathoms ; and finally Torres
Strait, in 3 to 11 fathoms. All these localities are near Cape York, at the extreme north
of Australia.

This interesting species is very remarkable on account of the denticulations on tlie
front margin, which are very strong for so small and delicate a shell.

Diplodonta amboinensis, n. sp. (PI. XIV. figs. 12-12a).

Testa subquadrata, convexa, albida, valde insequilateralis, postice lata, obtusa,
mediocriter arcuata, antice angustior, valde arcuata, incrementi lineis tenuibus (hie illic
paucis majoribus) sculpta, plus minusve, praecipue latum posticum versus, minute
subpunctata. Margo dorsi posticus elongatus, fere rectus, parum declivis, anticus valde
descendens, vix curvatus, brevior. Umbones parvi, antemediani, in j longitudinis
collocati.

Length 18 mm., height 15, diameter 10.

Habitat. — Amboina, Molucca Islands, in 15 to 20 fathoms.

200 THE VOYAGE OF H.M.S. CHALLENGER.

Like several other species of Diplodonta, this is mainly distinguished by its form. It
is somewhat square behind, and the minute subpunctation of the surface, which is chiefly
noticeable towards the hinder part, is a feature of some importance. The hinge and
interior are of the usual character.

Diplodonta sp.

Habitat. — Port Jackson, in 2 to 10 fathoms.

One right valve only was obtained. It is of an ordinary rounded form, only
moderately convex, as long as high, and presents the usual kind of concentric striation
and the normal dentition of hinge. It seems to be distinct from any of the species
previously recorded from the same district.

Diplodonta sp.

Habitat. — Station 135, Nightingale Island, Tristan da Cunha Islands, Mid South
Atlantic, in 100 to 150 fathoms.

Only a single left valve of this species was obtained. It is old and thickened, and
very closely resembles the British Diplodonta rotundata, but is rather more obtuse at the
anterior end. The limits of the species in this genus are very difficult to decide, as the
main character is that of form, whicli is a very variable one. In sculpture many of the
species are alike, and there is hardly any departure from white in the colouring, nor does
the dentition materially difi'er in many of the forms.

Diplodonta apicalis, Philippi.

Diplodonta apicalis, Philippi, Enum. Moll. Sicil., voL i. jj. 31, pi. iv. fig. 6, vol. ii. p. 24.
Habitat.— Teneriie, in 70 fathoms.

This species has already been recorded from the Canary Islands by the late
E. MacAndrew. It is considered by some authors identical with Diplodonta
trigonula, Bronn, but Philippi held them distinct. Not having had an opportunity of
consulting Bronn's description and figure, or of examining a specimen, I prefer to adopt
the name given by Philippi.

REPORT ON THE LAMELLIBRANL'HIA TA. ,201

Family Kelliid^.
KelUa, Turton.
Kellia suborbicularis (Montagu),

Ml/a siihorhiciilaris, Montagu, Test. Brit., pt. i. p. 39, .and pt. ii. p. 564, Suppl., pi. xxvi. fig. 6.

Kdlia suborbicularis, Turtou, Dithyra Urit., p. 56, pi. xi. figs. 5, 6.

Kellia suborbicularis, Forbes and Hanley, Brit. Moll., vol. ii. p. 87, pi. xviii. figs. 9, 9a, 96,

and Pi. O fig. 4.
Kellia suhorJiicidaris, II. and A. Adams, Genera Rec. Moll., vol. iii. pi. cxiv. figs. 8-8c'.
Kellia suborbicularis, Jefireys, Brit. Couch., vol. ii. p. 225, voL v. jjI. xxxii. fig. 2.

Habitat. — Station 149d, Royal Sound, Kerguelen, in 28 fathoms; volcanic mud.

Two specimens from this locality I cannot distinguish from this well-known
European species, which has not, I believe, been previously met with farther south than
the Canary Islands. One of them exhibited a very trifling difference in the hinge-plate,
which was not, however, maintained by the second example.

Kellia nuculina, Martens (PI. XL figs. 4-46).

Kellia nuculina, Martens, Sitzungsberichte GeseUsch. naturf. Freunde, EorUn, 1881, p. 79.
Testa minuta, ovata, albida vel pallide straminea, nitida, concentrice minute striata,
modice couvexa, inaequilateralis ; umbones involuti, multum promiuentes. Dentes
cardinis validi, lateralibus apice haud remotis.

This minute shell is ovate, rather inequilateral, fairly convex, whitish, glossy,
iridescent, and sculptured with very fine lines of growth. The ends are almost equally
rounded, but the anterior is a trifle narrower than the posterior. The beaks are not very
acute at the tips, and rather elevated above the curved hinge-line. The dentition of thi
little shell is rather well-marked. The right valve has a well-developed cardinal tooth in
front of the umbo, and a second very slender one above, between it and the dorsal edge.
The hinder lateral tooth in this valve is almost as near the beak as the cardinals, elevated,
and separated from the outer margin by a broad deep groove. The two cardinals of the
left valve are united above, forming a single angular tooth, and the posterior lateral is
thick and elevated. The hinge-plate is continuous under the beaks, so that a rather
large and somewhat triangular space occurs for the reception of the ligament.

Length 4-i- mm., height 3-J, diameter 2.

Habitat. — Ofi' Christmas Harbour, in 120 fathoms; and Balfour Bay, Kerguelen
Island, in 20 to 60 fathoms ; also ofi" Prince Edward Island, in 50 to 150 fathoms.

This species may at once be distinguished from Kellia suborbicularis by its diff"erent
hinge and form. Not feeling perfectly certain with regard to the identification of these
specimens, I therefore have given the above description.

(ZOOL. CUALL. EXP.— PAKT XXXV.— 1885.) Mm 26

202 THE VOYAGE OF H.M.S. CHALLENGER.

Kellia rotunda, (Deshayes), var. (PI. XI. figs. b-bh).

Erycina rotunda, Desliayes, Proc. Zool. Soc. Lond., 1855, p. 18L
Kellia rotunda, Angas, Proc. Zool. Soc. Lond., 1867, p. 927.

Habitat. — Station 162, off East Moncoeur Islaucl, Bass Strait, iu 38 fathoms
(Challenger) ; Port Jackson (Challenger and Angas) ; also Newcastle, New South Wales
(Angas) ; Moreton Bay (Deshayes).

The single specimen obtained by the Challenger at Port Jackson is considerably
larger than any other that I have ever seen, and exceeds the dimensions of the types
described by Deshayes. It is 14 mm. in length, nearly 13 high, and 8 in diameter.
The form is hardly as rotund as that of the Moreton Bay specimens, for with age the
posterior side appears to enlarge more rapidly so that the large shell under examination
is rather more inequilateral. The specimens from Bass Strait exhibit a precisely similar
outline, and consequently approach very closely the Kellia cycladiformis of New Zealand,
and, indeed, I am rather inclined to believe that they will prove eventually variations
of one and the same species. The specimen in Mr. Cumings' collection from North
Australia (Jukes), assigned by Deshayes to his Erycina cycladiformis, is very different
in form from the shells from New Zealand. It is rounder, having the anterior end
narrower than the posterior, which is the reverse in the latter s^iecimens as a rule, and
not weU shown in Deshayes's figure. Among a series of Kellia cycladiformis from New
Zealand, presented to the British Museum by Colonel Bolton, there is a specimen of
unusually large size, whose dimensions are worth recording. It is 17g mm. long, 15
high, and 11 in diameter, an averaged sized specimen being about 12 in length, 10 iu
height, and 8 in diameter. The hinge-characters are precisely similar in l)oth forms.

Kellia cardiformis, n. sp. (PI. XI. figs. 6-66).

Testa globosa, fere sequilateralis, tenuis, subcircularis, alba, liris confertis radiantibus
tenuissimis ornata, incrementique lineis concentricis sculpta. Umbones leviter supra
marginem dorsalem producti, ad apices obtusi, politi. Latus anticum regulariter
arcuatum, posticum altius, minus curvatum, superue obtuse humerosum. Denies
cardiuales valvse sinistrse duo subvalidi, partem anticam versus inclinati, in dextra unicus
obliquus, subbipartitus ; dens lateralis posterior in utraque valva elongatus, gracilis, in
sinistra margine dorsali sulco angusto separatus.

This little Cardium-like species is very thin, rather globose, somewhat circular and
nearly equilateral. It is whitish, slightly glossy, sculptured with very fine radiating
sulci with intervening rounded ridges which are crossed by fine concentric lines of
growth. The hinder dorsal margin is higher than the front and less oblique, and joins

REPOKT ON THE LAMELLIBRANCHIATA. 2U3

the lateral outline in a rounded angle. The side itself is only slightly excurved, whilst the
opposite margin is semicircularly arched, as is also the basal edge. The umbones are
slightly elevated above the hinge-line, and terminate in obtuse circular glossy shield-like
bosses. The hinge is composed of two cardinal teeth in the left valve and a single one in
the right. They slope forwards and are strong for so fragile a shell. In the right valve
there is also an elongate slender lateral tooth, parallel with the hinder dorsal margin,
from which it is separated by a narrow furrow, into which fits a corresponding tooth in
the other valve. The internal ligament is small, situated immediately beneath the obtuse
apices and behind the cardinal teeth in both valves. The interior is rather glossy, and,
owing to the thinness of the shell, exhibits the radiate character of the external sculpture,
which produces a crenulate margin to the valves.

Length 6 mm., height 6, diameter 4^^.

Habitat. — Station 194d, Royal Sound, Kerguelen Island, in 28 fathoms ; volcanic mud.

This curious little species externally is not unlike a delicately sculptured Cardium.

Kellia adamsi, (Angas).

Lepton adamsi, Angas, Proc. Zool. Soc. Lond., 18G7, j^p. 910, 911, and 928, pi. xliv. fig. 11.

Habitat. — Port Jackson, in 2 to 10 fathoms.

Only a single right valve in poor condition was obtained. This species is wrongly
placed in the genus Lepton, for the hinge-characters are (|uite different from those of that
genus, but agree perfectly with those of Kellia rotunda, Kellia suborbicularis, &c. No
doubt it was the punctate surface down each side of the valves which misled Mr. Angas
in the location of this interesting species.

Montaciita, Turton.
Montacuta paula (A. Adams) (PI. XII. figs. l-\b).

P(/thtna jjaula, A. Adams, Proc. Zool. Soc. Lond., 1856, p. 47.
Pijthina peculiar's, A. Adams, up. cit., p. 47.

Habitat. — Station 188, south of New Guinea, in 28 fathoms (Challenger); Paine
Island, Torres Strait (Adams); Ceylon for Pythina pecidiaris (A. Adams).

I have very carefully studied the two forms, which I here unite as one species, and
have come to the conclusion that the shell described as Pythina peculiaris is merely
unusually distorted. The " tout ensemble " of the specimen, with the exception of the
outline, is quite like that of Pythina paida, it is similarly sculptured, of the same texture,
and has precisely the same dentition. This consists, in one valve (which may be regarded
as the right), of two widely divergent cardinal teeth separated from the dorsal margins

204 THE VOYAGE OF H.M.S. CHALLENGER.

by a deep groove. The anterior is rather shorter than the posterior, and l)oth are pro-
longed some distance parallel with the dorsal edges, and form, as it were, lateral teeth
also. In the other valve (the left?) the edge is prominent on each side so as to fit in the
grooves in the opposite valve. Between the divergent cardinals under the umbones is
a triangular space which receives the internal ligament.

Pythina arcuata, A. Adams, from the Philippine Islands, is a more inequilateral
species, with a less incurved ventral margin, and is difi"erent in the hinge, the posterior
tooth of the right valve being shorter than the front one, and neither laterally continued
as in Pythina paula.

From the above description of the hinge of this species it will be seen that it would
be more correctly placed in the genus Montacuta.

The dentition of the type of Pythina [Pythina deshayesiana, Hinds) is exactly that
of Kellia, and the fact of the shell being divaricately plicate does not in my opinion
entitle it to generic rank, but may perhaps be regarded of subgeneric importance.

A few other species which have been described as PythinoB should certainly be placed
in the genus Kellia, such are Pythina mactroides, Hanley,^ and Pythina nuculoides,
lia,nlej^ = Erycina denticulata,Deshiiyes.^ Pythina cumingii, A. Adams,* does not quite
agree with Kellia in dentition, having two teeth on each side in the right valve and a
single one on each side in the left which fit in between those of the other valves. Two
other species, Pythina arcuata, A. Adams,' and Pythina triangidaris," A. Adams =
Mactra nucleus, (Conrad 1) Eeeve,' should be placed in the genus Montacuta and Pythina
stowei, Hutton,* although not absolutely identical as regards the hinge, sufticiently
resembles Pythina deshayesiana as to be placed in the same subgeneric section, having
similar divaricate sculpture.

Montacuta angasi, n. sp. (PI. XII. figs. 2-26).

Testa subaequilateralis, mediocriter convexa, ovalis, albida, vel dilutissime fuscescens,
vix nitida, incrementi lineis tenuibus striata. Latus anticum obtuse rotundatum,
posticum acutius ; margo ventris late, regulariter curvatus. Umbones fere mediani,
paulo supra marginem producti. Dentes laterales approximati, erecti. Pagina interna
subnitida, pallidissime fuscescens, radiatim obsolete substriata. Cicatrices profundse,
fere sequales, linea pallii simplice bene impressa junctse.

This species is longish oval, rather more pointed behind than in front, obscurely
subtransparent, dirty whitish-brown, and sculptured with fine lines of growth. It is

' Proc. Zool. Soc. Lond., 1856, p. 340. ■■' Loc. cit., p. 341. ^ Op. cit., 1855, p. 182.

•• Op. cit., 185G, p. 47. ^ y^,_ ^ ,7^ i856, p. 47. " Op. cit., 1856, p. 47.

' Coach. Icon., fig. 102 (gen. Madm). * Cat. Marine Moll. New Zeal., p. 76; Manual Moll. New Zeal, p. 157.

REPORT ON THE LAMELLIBRANCHIATA. 205

nearly equilateral, moderately convex, and lias l)ut little gloss upon the surface. The
dorsal margin is not much curved near the umbones, but gradually rounds off into the
sides, and the ventral outline is regularly widely arcuate, and a little more ascendant
posteriorly than in front. The umbones are not very acute, central, and just a little
raised above the hinge-line. Tlie divergent lateral tooth on each side in the right valve
is prominently raised, there being a wide triangular space between them under the umbo.
The interior is not highly glossy, but exhibits traces of faint radiating striae, principally
towards the margin. The muscular scars are deep, shining, and united by a simple
distinct pallial line.

Length 5^ mm., height 4, probable diameter of a perfect specimen 2|.

Ilahitat.^-'Povt Jackson, New South Wales, in 2 to 10 fathoms.

Unfortunately only a single right valve of this species was dredged. It is, however,
of sufficient importance to merit description, as it appears to be an addition to the fauna
of Port Jackson, the MoUuscan portion of which has been catalogued and described by
my friend G. French Angas, after whom I have named the species.

Montacuta acuminata, n. sp. (PI. XII. figs. 3-3/>).

Testa parva, tenuis, semitranslucida, vitreo-alba, nitida, incrementi liueis tenuissime
striata, subsequilateralis, ovato-triangularis, utrinque aliquanto acuminata, postice breviter
subrostrata. Margo dorsi utrinque valde declivis, antice leviter arcuatus, postice
rectiusculus. Margo inferior late curvatus, latus posticum versus hand profunde
sinuatus. Umbones parvi, acuti, fere mediani. Dentes valvee dextrjB duo, quorum
anterior prope umbonem locatus, posterior magis remotus, elongatus. Pagina interna
nitida, radiatim substriata. Sinus pallii mediocriter magnus, latus.

This species is rather triangular, being acutely rounded in front and shortly beaked
behind. It is very thin, semitransparent, hyaline, marked only by very fine lines of
growth, rather inflated, and almost equilateral. The dorsal outline is very sloping on
both sides of the beaks, the angle of divergence being about 108°. On the anterior side
it is slightly excurved, but behind is nearly straight and sharply bent at right angles to
the surface of the valves, formingr a flat linear dorsal area. The ventral margin bulges
somewhat at the middle, gently curves upwards anteriorly, and exhibits behind a faint
sinuation. The beaks are about central, small and acute. The left valve possesses no
teeth, and displays merely a slight thickening of the dorsal edge, ju.st in front of the
apex. The scar of the internal ligament in this valve is oblique, and under the posterior
dorsal margin near the uml:)o. In the right valve there are two teetli, the one thin, shortish,
erect, close to, but in front of the umbo, the other more remote and longer. The interior
of the valves is glossy, faintly concentrically grooved near the lower margin, and more or

206 THE VOYAGE OF H.M.S. CHALLENGER.

less distinctly radiately substriated. The pallical sinus is broadly curved, and reaches
about one-third of the length across the valves.

Length 6 mm., height 5, diameter 3.

Habitat. — Station 185b, east of Cape York, North Australia, at a depth of
155 fathoms; coral sand.

Young shells do not show so much tendency to posterior rostration as those more
adult.

Montctcuta cylindracea, n. sp. (PI. XII. figs. 4-46).

Testa elongata, cylindracea, valde couvexa, insequilateralis, albida, utrinque rotundata,
increment! lineis tenuibus striata, epidermide tenui fibrosa prsecipue prope marginem
induta. Margo dorsi longior (anticus X) horizontalis, levissime arcuatus, brevior
(posticus ?) oblique curvatus. Margo ventralis late arcuatus utrinque ascendens.
Umbones subacuti, paulo elevati, circiter in \ longitudinis collocati. Pagina interna
alba, nitida. Cardinis margo aliquanto incrassatus, fossa obliqua" ligamentum continente
postice munitus. Cicatrix muscularis antica elongata, postica brevior, rotundata.

This species is very elongate and very inequilateral. It is rather cylindrical, rounded
at both ends, a little wider in front than behind, and considerably swollen. It is
moderately strong for the genus, sculptured with fine concentric lines of groMi^h, whitish,
clothed inore or less, especially towards the outer margin, with a pale yellowish fibrous
epidermis, which is narrowly reflexed within the valves. The longer, or what I consider
the anterior dorsal margin, is horizontal and faintly excurved ; the posterior, being very
much shorter, descends obliquely and is somewhat arcuate. The lower outline is only
slightly convex, and ascends rather more abruptly behind than in front. The umbones
are moderately acute, a little raised above the hinge-line, and situated at about a fourth
of the entire length from the posterior extremity. The hinge-plate is slightly thickened,
especially behind the beaks, where there is a shallow oblique pit or socket for the recep-
tion of the ligament. The interior of the valves is white and a little glossy. The
anterior muscular scar is very long, the posterior shorter, broader, and rounder.

Length 15 mm., height Sg, diameter 7.

Habitat. — North Atlantic, in deep water.

This species is remarkable on account of its cylindrical form, the convexity of the
valves, and its comparative solidity.

Montaciita occidentalis, n. sp. (PI. XII. figs. 5-56).

Testa transversim ovata, minuta, tenuis, valde insequilateralis, utrinque rotundata,
antice angustior, alba, nitida, incrementi striis minutis sculpta. Margo dorsi anticus

EEPORT ON THE LAMELLIBKANC'HIATA. 207

brevissimus, infra umbones leviter concave obliquus, posticus elongatus, primo rcctiusculus,
fere horizontalis. Umbones parvi, acuti, antrorsum iuclinantes, antemediani, circiter in
^ longitudinis coUocati. Valva sinistra dente unico ereeto lamelliformi utrinquc nnmita,
dextra marginibus dorsalibus lamelliformibus subdentata. Ligamentum intormim iufra
umbones situm.

A single specimen is all that is at present knowTi of this species. It is very small,
moderately convex, ovate, rather narrower in front than behind, very inequilateral, thin,
white, glossy, and sculptured with excessively fine lines of growth. The front dorsal
margin is short, a little oblique, just a trifle excavated before the umbones, then some-
what arcuate and gradually rounding into the sharply curved extremity. The posterior
margin is much longer, at first almost horizontal and straight, afterwards becoming a
little arcuate and oblique. The ventral outline is widely curved and equally ascending
at both ends. The beaks are small, curved over towards the front, very slightly
produced, and situated in advance of the middle, at about one-third of the total length
from the anterior end. The left valve has two erect lamellar very divergent teeth, of
which the posterior is rather more strongly developed. Tliey are separated by a broad
triangular space, and stand out free from the outer margin. The right valve has no
distinct teeth, but has the dorsal margin on each side elevated into thin prominences,
which when the valves are closed fit into the grooves between the teeth and dorsal margins
of the other valves. The ligament is internal, and situated beneath the umbones. All
the muscular impressions on the inner glossy surface ai*e indistinct.

Length 2^ mm., height if, diameter Ij.

Habitat. — Station 24, ofi"Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

It is impossible to say whether the above figures represent the full size attained by
this species, but probably they do not.

Montacuta pura, n. sp. (PI. XII. figs. 6-66).

Testa elongata, valde insequilateralis, tenuissima, alba, incrementi lineis tenuibus
striata, utrinque rotundata, postice paulo angustata. Margo dorsi anticus elongatus,
levissime arcuatus, fere horizontalis, posticus brevior, oblique curvatus. Margo inferior
latissime curvatus. Umbones parvi, paulo supra marginem product!, ad apicem obtusi,
longe pone medium coUocati. Dens cardinalis unicus in valva dextra infra apicem situs,
in sinistra nullus.

This little species is remarkably oblong, very fragile, white, very inequilateral,
obtusely rounded at the anterior end, and a little narrower at the opposite extremity.
It is smooth, glossy, rather convex, and sculptured only by the very fine concentric lines

208 THE VOYAGE OF H.M.S. CHALLENGER.

of growtli. The front dorsal margiu is long, scarcely at all oblique, and only very faintly
excui-ved. The hinder slope is very much shorter, much more sloping and more curved.
The ventral outline is widely curved, without any sinuation. The umbones stand out a
little above the dorsal margin, are situated about one-third of the total length from the
posterior end, and terminate in a minute obtuse apex. There is in the right valve a
single tubercular tooth beneath the umbo, and an elongate groove within the margin on
the anterior side, for the reception of the raised edge of the opposing valve. Within
the posterior margin, at a short distance from the apex, there is a slight denticular
prominence, beneath which is found the oblique groove containing the internal ligament
which extends as far as the anterior denticles. In the left there is scarcely any indica-
tion of teeth, but the denticular prominence on the posterior side, supporting the
ligament, is fairly conspicuous. The muscular scars and the pallial impression are
indistinct.

Length 6^ mm., height 4, diameter 2f. *"

Habitat. — Station 75, off Fayal, Azores, in 450 fathoms, volcanic mud; and Station
VIIL, oif Gomera, Canaries, in G20 fathoms, volcanic mud.

This curious little species is remarkable for its oblong, inequilateral form, and is quite
distinct from Montacuta cylindracea, which is proportionally less elongate, has a shorter
internal ligament, and only the faintest indication of a groove within the anterior dorsal
margin of the right valve.

In form this species closely resembles Montacuta ferruginosa, Montagu, but is rather
more convex, has more prominent beaks, and different hinge-characters.

Famdy S o l e M y i d ^.
Solemya, Lamarck.

Solemi/a patagonica, n. sp. (PL XL figs. l-lo).

Testa oblonga, postice paulo angustata, antice sensim latior, arcuatim truncata,
epidermide crassa, nigro fusca, radiatim lirata et sulcata, ad marginem profunde scissa
longeque extra valvas producta, induta. Linea dorsi ante umbones intus incx-assata,
'densatione paulo ante medium aliquanto intra marginem producta. Pagina interna
radiatim obsolete subcostata, costa obliqua submediaua cseteris majore. Cicatrix postica
profunda, oblonga, inferne linea elevata marginem dorsalem anticum versus producta,
marginata ; cicatrix antica magna, subpyriformis.

Length 31 mm., height 11, diameter 6.

Habitat. — Station 311, off west coast of South Patagonia, in 245 fathoms.

This is very like other species of the genus in general appearance, but may be

REPORT ON THE LAMELLIBRANCHIATA. 2()0

recognised by a certain difference of form and other characters within the valves. It is
more trimcate at the anterior or broader end than any otlier species with which I am
acquainted. It is rather flatter than Solemya j^arkinsonii, Gray, from which it also
diifers in having a thickening along the front dorsal edge within the valves, which
extends as far as the anterior muscular scar, where it diverges obliquely somewhat from
the margin. Another distinguishing feature is the slender lu'a or raised line which
borders the anterior side of the hinder deep scar, and then runs obliquely upwards as far
as the middle of the front dorsal thickening. What portion of the ligament may have
been internal I am not able to state positively, as only a single specimen was obtained,
and that in a dead condition. A part of it may have rested in a slight transversely
striated depression, or shallow groove, along the dorsal edge, both in front of and behind
the beaks, but I do not think any portion of it was produced within at right angles to the
dorsal margin, as in Solemya parkinsonii and Solemya australis.

Family A s t a R T i D ^.

Subfamily AsTARTiN.a;.
Astarte, J. Sowerby.

Astarte macandreivi, Smith (PI. XV. figs. 1-la).

Astarte macandrewi, Smith, Journ. Conch., vol. iii. p. 228.
Habitat. — Tenerife, in 70 fathoms.

This minute form was originally described from specimens collected by the late
Robert Macandrew at the Canary Islands, and the distinctions betw^een it and Astarte
triangularis are pointed out in the paper above referred to.

Astarte magellanica, Smith.

Astarte magellanica, Smith, Proc. Zool. See. Loud., 1881, p. -11, pi. v. fig. 7.
Astarte maijeUanka, Smith, Journ. Conch., vol. iii. p. 226.

Habitat. — Prince Edward and Marion Islands, in 100 and 150 fathoms.

The specimens from these localities are either finely concentrically ribbed or have the
ridges rather less distinct. In neither case are they so strong as in the single iy^a from
Boija Bay in the Strait of Magellan. Being smoother shells they more nearly resemble
as regards sculpture Asta7'te longirostra, d'Orbigny, from the Falkland Islands. They
difl"er, however, from that species in being less beaked at the umbones, and all have the
inner edge of the valves finely crenulated with the exception of one small specimen which
is evidently not full grown, a further proof (if any were needed) that the crenulation of

(zool. chall. EXP. — PART xxxv. — 1885.) , Mm 27

210 THE VOYAGE OF H.M.S. CHALLENGER.

the margin is a sign of maturity. As d'Orbigny's typical specimens in the British
Museum are hirger than any as yet known of Astarte magellanica, and have smooth
margins to the valves, it seems likely that that species has not wrinkled edges. This,
however, is uncertain, as the adult shell possiljly has yet to be discovered.

Subfamily Carditin.e.

Cardita, Brugiere.
Cardita calyculata (Linu^).

Cardita calyculata, Lamarck, Aniin. sans vert., vol. vi. p. 24.
Cardita calycidata, Philippi, Enum. Moll. Sicil, vol. i. p. 55.
Cardita muricata, Sowerby, Proc. Zool. Soc. Lond., 1832, p. 195.
Cardita muricata, Reeve, Conch. Icon., vol. i. pi. iv. fig. 18, var.

Habitat. — -Station 162, oif East Moncoeur Island, Bass Strait, in 38 to 40 fathoms,
and off Tenerife, in 70 fathoms.

After a careful comparison of the few small valves from Bass Strait, with sjjecimens
of the same size from the coast of Piedmont, I am unable to detect any good and sufficient
reasons for separating them specifically. The number of cost» is the same, but a few of
them upon the anterior half of the valves may perhaps be slightly coarser in the shells
under examination than in those from the Mediterranean, and the anteiior end in the
latter does perhaps project forward rather further beyond the umbones than in Australian
shells. The hinge, however, is absolutely identical in both.

Cardita muricata of Sowerby, said to have been found at Crescent and Eapa Islands,
and of which there is a specimen in the British Museum from Nairai, Fiji Islands, does
not, in my judgment, present any satisfactory distinctive features.

The shell figured by Reeve under this name has the posterior ribs closer together
than in the types described by Sowerby.

Cardita excavata, Deshayes.

Cardita excavata, Desliayes, Proc. Zool. Soc. Lond., 1852, p. 100, pi. xvii. figs. 1-3.
Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

Three or four other forms of Cardita, viz., Cardita essingtonensis, Deshayes, Cardita
umbilicata, Deshayes, and Cardita pica. Reeve, are very closely allied to the present
species, and will probably eventually prove to be variations of the same shell. If the
spotting and fine reddish lines on the ribs of this species were not somewhat peculiar, I
should feel no hesitation in uniting it with Cardita essingtonensis or Cardita p)ica or
Cardita umbilicata, these so-called species evidently belonging to one and the same.

REPORT ON THE LAMELLIBRxVNCHIATA, 211

Cardita canaliculata, Eeeve.

Cardita canaliailafa, Reeve, Conch. Icon., vol. i. fig. 40.

Cardita cardioides, Reeve, he. cit, fig. 49.

Oardita mmingii, Deshayes, Proc. Zool. Soc. Lend., 18.52, p. 102, p], xvii. fig. 1.5.

Habitat. — Station 212, Malanipa, Basilan Strait, Philippine Islands, in 10 fathoms;
.sand.

On closely comparing the above forms, I fail to appreciate any just grounds for their
separation. Cardita crermlata, Deshayes, is also very similar, and will in all probability
eventually prove to be but a slight variety, the hinge being exactly the same in all.

Cardita beddomei, n. sp. (PL XV. figs. 5-5a).

Testa insequilateralis, subtrigono-rotundata, crassiuscula, mediocriter convexa, albida,
postice rufo notata, costis tenuibus radiautibus nodulosis circa 25 (sulcis intervenien-
tibus subfequalibus) instructa : margo dorsi posticus valde declivis, vix curvatus,
ventralis parum arcuatus. Umbones promineutes ; lunula parva, cordata, laevis.

Var. Testa magis quadrata, costis circa 27 instructa.

This species is considerably inequilateral, moderately convex, thickish, trigonally
rounded, whitish and dotted and spotted with a reddish colour down the posterior side.
It is ornamented with about twenty-five fine radiating ribs, which are either equal to the
intervening sulci or rather broader, and covered with numerous small nodules or solidi-
fied scales which are more or less compressed, especially those near the ventral margin.
The beaks in the typical form are well raised, so that the dorsal margins become very
oblique on both sides. The posterior is long and only very slightly excurved, the
anterior in the region of the small cordate smooth lunule being a little excavated.

The interior is white, with a tinge of pale red towards the umbones.

Length 17 mm., height 16, diameter 11.

Habitat. — Station 162, oflf East Moncceur Island, Bass Strait, in 38 to 40 fathoms.

In the British Museum there are two or three specimens dredged in Bass Strait by
Macgillivray during the voyage of the " Eattlesnake " which slightly vary from the
Challenger specimen. They are rather more quadrate, and have a few additional costa;.

This species closely resembles Cardita bimacidata of Deshayes from New Zealand,
but has more numerous ribs, less epidermis, a shorter lunule, and lacks the orange colour
on the muscular impressions.

Cardita bimaculata, Deshayes.

Cardita bimaculata, Deshayes, Proc. Zool. Soc. Lend., 1852, p. 102, pi. xvii. figs. 4, 5.
Testa subquadrata, valde insequilateralis, modice convexa, albida, pallide rufo punctata.

21-2 THE VOYAGE OF H.M.S. CHALLENGER.

epidermide olivacea induta, costis radiantibus tuberculatis circiter undeviginti instructn,
incrementi lineis in interstitiis sculpta. Luuula parva, fuscescens, elongato-cordata,
impressa. Margo dorsi posticus rectiusculus parum obliquus, anticus leviter concavus,
valde declivis, brevior. Latus posticum latum, rotunde subtruncatum, anticum angustius
rotundatum. Margo ventris late curvatus. Umbones in. circa ^ longitudinis collocati.

This species is considerably longer than high, somewhat square, broader behind
tiaan in front, very inequilateral, and moderately convex. It is white, sjjotted upon the
ribs with pale red, and more or less covered with an olive epidermis. The sculpture
consists of about nineteen radiating costas, which are rather slender, about as broad as
the intervening sulci, and covered with small compressed nodules. In addition the
grooves are crossed with rather strongly marked lines of growth. The kxnule is generally
tinged with brown, somewhat impressed, and elongate cordiform. The beaks are placed
well towards the front, being about one-fourth of the length from that extremity.
The central tooth of the right valve is large, white, acute above, and triangular, the two
of the left valve diverging, and much smaller. The muscular scars are orange or bi-owu,
and the inner margin of the valves is strongly dentate.

Length 13 mm., height 11^, diameter 9.

Habitat. — Station 162, off East Moncoeur Island. Bass Strait, in 38 to 40 fathoms.

This species was originally described by Deshayes from specimens said to have been
collected in New Zealand, a locality not since confirmed, for Captain Hutton, in his
Manual of New Zealand MoUusca, includes this species in the fauna of that country
merely on the authority of the type-shells.

Cardita astartoides, Martens (PI. XV. figs. 2-2c).

Cardita astartoides, Martens, Sitzungsberichte Gesellscli. Nat. Freunde, Berlin, 1878, p. 25.

Testa suborbiculata, crassa, antice et postice subsequaliter rotundata, margine dorsali
antico concavo, postico convexo, gibbo, margine ventrali sequaliter arcuato ; costis radianti-
bus latiusculis circa 18, parum elevatis, interstitia subsequantibus et lineis concentricis
undulatis costas seque ac interstitia percurrentibus sculpta, periostraco crasso, uigrofusco
costas suboccultante vestita. Dens cardinalis medius valvse dextrte interdum distincte
bifidus, anticus valvse sinistrae subvalidus, trigonus, lateribus perpendiculariter decisus ;
impressio muscularis antica elongata, postica brevior.

Length 31 mm., height 27, diameter 15.

Habitat. — Station 149, Eoyal Sound, at Balfour Bay, Kerguelen Island, in 20 to 60
fathoms ; and Station 150, between Kerguelen and Heard Islands, in 150 fathoms.

This species, as pointed out by Martens, bears a great resemblance to the Nortli
American Cardita borealis of Conrad, and may be regarded as the southern representa-

REPORT ON THE LAMELLIBRANCHIATA. 213

tive of that form. It certainly is more like that species than Cardita velutina, Smith,
from South Patagonia, which we should not expect, considering how similar tlic fauna of
that region and of Kerguelen Island appear to be.

Cardita astartoides is a much flatter and larger species than the Patagoniau shell,
and has much feebler radiating ribs.

The young of this species is clothed with a straw-coloured epidermis, and appears to
be proportionally longer than the adult shell.

Cardita sp.

Habitat. — Port Jackson, iu 2 to 10 fathoms.

Only a single right valve of this species, which I have not been able to identify, was
obtained. It is scjuarish behind, narrowed in front, and covered with about twenty
slender ribs, bearing numerous prickly hollow scales. The intervening sulci are deep,
and just a trifle broader than the costse. It is whitish and spotted with pale red upon
the ridges, and the minute sunken cordate lunule is also stained with the same colour.
The interior is faintly radiately grooved, the grooves corresponding to the external ribs.
Length 9 mm., height 7.

Cardita dilecta, n. sp. (PI. XV. figs. 4 -4a).

Testa mediocriter insequilateralis, subglobosa, parum crassa, antice rotundata, postice
latior, minus rotunda, costis circiter 28 confertis, minime elevatis, striis concentricis
numerosissimis sculptis instructa, albida rufofusco irregulariter notata et maculata.
Lunula subprofunda, elongato-cordata. Margo dorsi posticus obliquus, rectus, anticus
valde declivis, vix concavus. Pagina interna albida, plus minusve rufo tincta, margine
denticulato circumdata.

This little Carc^m ni-shaped species is rather thin and inequilateral, whitish or whitish-
i)rown, variegated with short streaks of reddish-brown on the costse, and stained down
the posterior side with the same colour. It is sculptured with narrow radiating impressed
lines, which leave between them about twenty-eight very little elevated round-topped
ribs which are cut across by very numerous concentric striae, producing very narrow
transverse tubercles upon the costse. The tubercles are about equal iu width all over the
valves, but a few down the hinder side are separated by rather broader grooves than the
rest. The lunule is moderately deep and elongate heart-shaped. The hinge consists of a
single conical cardinal tooth in the right valve, which fits in between two teeth in the
left valve, whereof the posterior is very long and slender, forming the lower support of
the ligament. The interior appears to be whitish, and more or less tinged with red.

Length 8 mm., height 6, diameter 5^.

214 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat. — Station 162/ off East Moncoeur Island, Bass Strait, in 38 to 40 fathoms.
This pretty species is remarkable for the depressed closely-packed costse, and the very
numerous narrow transverse tubercles upon them.

Cardita insignis, n. sp. (PI. XV. figs. 3-36).

Testa parva, alba, mediocriter convexa, subcircularis, suba^quilateralis, liris confertis,
radiantibus aliisquc concentricis magis remotis concinne caneellata, plicis radiantibus
3 to 4 utrinque undulata. Umbones parvi ad apicem Iseves. Margo valvarum
iuternns utrinque fortiter denticulatus, inferne simplex, acutus. Dentes cardinales duo
in utraque valva, quorum auticus valvse sinistrse et posticus dextrse crassi, triangulares.
Cicatrices elongatse, et linea pallii simplex. Ligamentum marginale.

This little species is as high as or even a trifle higher than long, fairly convex, rather
circular, equilateral, and for so small a shell not very thin. It is white and minutely
cancellated with numerous close-set very fine radiating lirse, and other concentric ones,
which are, however, much farther apart. Besides this ornamentation the valves exhibit
on each side three or four radiating depressions or folds, which impart a strongly dentate
character to the inner margin, which is smooth elsewhere. The beaks are small, smooth
at the tip, which inclines over towards the front. The dentition is strong. In the right
valve there are two cardinal teeth, the posterior being much thicker than the other, from
which it is separated by a triangular pit. The left valve also has two cardinals, but in
this instance the anterior, immediately beneath the apex of the umbo, is far the stouter,
the posterior being oljlique and slender. The muscular scars appear to be rather long on
both sides, and the pallial line simple.

Length 3i mm., height 3^, diameter 2^.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

This species will readily be recognised by the remarkable lateral sculpture and the
strongly dentate margin. It is a small Lncina-like shell, but judging from the hinge-
characters belongs to the genus Cardita.

Cardita (Thecalia) concamerata (Chemnitz).

Gliama concamerata, Chemnitz, Conch. -Cab., vol. vii. p. 138, pi. 1. fig. 506.

Chama concamerata, Wood, Ind. Test., pi. ix. fig. 15.

Cardita concamerata, Bruguiere, Ency. M6th., p. 138, pi. ccxxxiv. fig. 6.

Cardita concameirUa, Reeve, Conch. Icon., vol. i. figs. 42, a, I).

Cardita concamerata, Krauss, Siidafr. Moll., p. 13.

MytiJlcardia [Thecalia) concamerata, Chenu, Man. Conck, vol. ii. p. 136, figs. 652 and 654.

Mi/tilicardia {Thecalia) concamerata, H. and A. Adams, Genera Eec. Moll, vol. ii. p. 489.

Tliecalia macrothcca, Adams and Angas, Proc. Zool. See. Lond., 1864, p. 39.

Habitat. — Sea Point, Cape Town.

REPORT ON THE LAMELLIBRANCHIATA. 2V)

On comparing the type of Thecalia macrotheca presented to tlie British Museum b)^
G. F. Angas, Esq., with South African specimens of this well-known form, I cannot detect
the slightest difference. With the above type Mr. Angas also gave four specimens with-
out any internal cup-like process, which may be the male, if the sexes really be separate,
as stated by Messrs. H. and A. Adams, of Cardita concamerata. Adams and Angas
mention that this cup-shaped appendage is much larger in their species than in the Cape
shell. As the size of this is found to vary when a good series of specimens is examined,
this difference, which I do not observe, however, in the type, seems to me of little
importance. On opening one of the Challenger specimens the cup was found to contain a
number of fry. The foot is small, cleft at the bottom, and furnished with a byssus.

Two specimens which have no sinuation at the ventral margin, and lack the internal
cup, are probably males. They are rather squarer at the anterior end, and the ridges down
the hinder part are finer and one or two more in number.

Carditella, Smith.

Carditella exidata, n. sp. (PL XV. figs. 6-6«).

Testa transversa, subquadrata, crassiuscula, valde inEequilateralis, albida, mediocriter
convexa. costis radiantibus circa quatuordecim rotundatis, concinne squamulatis instructa.
Latus anticum fere perpendiculariter truncatum, posticum latins, rotundatum. Margo
dorsi horizontalis, rectus, ventralis late arcuatus. Umbones parvi, acuti, fere terminales.
Pagina interna nitida, alba, radiatim sulcata.

This minute species, externally, is very much like the young of Cardita calyculata,
but more finely squamulated, and without the slight sinuation in the ventral margin
occurring in that species. It is whitish, very inequilateral, squarish-oblong, obliquely or
almost perpendicularly truncate in front, rather broad and rounded behind. The dorsal
margin is about horizontal and rectilinear, and the ventral very gently arcuate. The
beaks are small, acute, and all but terminal. The sculpture consists of about fourteen
radiating rounded ribs, of which those on the hinder half of the valves are considerably
broader than the rest, and separated by broader and deeper grooves, which do not, how-
ever, equal in width half that of the ribs, which are finely and closely scaled throughout.
The interior of the valves is glossy, white, and radiately^ grooved, the grooves correspond-
ing to the external costal. The hinge consists of a single central conical triangular tooth
in the right valve, which fits in between two more slender divergent teeth in the left.
The lateral teeth are well developed and equidistant.

Length 4 mm., height 2f, diameter 2.

Habitat. — Station 135, off" Nightingale Island, Tristan da Cunha, in 100 to loOfathoms.

This pretty little species is more oblong and inequilateral than any of the other
forms belonging to this genus, all of which are shells of very small size.

216 THE VOYAGE OF H.M.S. CHALLENGER.

Carditella capensis, n. sp. (PI. XV. figs. 7 -7c).

Testa parva, sequilateralis, mediocriter eompressa, triaugulariter ovata, albida, irregii-
lariter rufo notata, costis radiantibus tenuibus pulcherrime uodidosis circiter 18
instructa. Margo dorsi utrinque levissime concavus, ventralis mediocriter arcuatus.
Dentes cardinales duo insequales in utraque valva, antico valvse dextrae magno, conico,
triangulari. Laterales utrinque distincti, ajquidistantes. Ligamentum parvum, internum,
infra umbones locatum. Cicatrices subprofundge, magnse. Margo ventris intus duplex,
dentatus.

This is a fairly solid little species, triangidarly ovate, angular above, curved below,
and rather sharply rounded at the sides. It is moderately compressed, about equilateral,
white, and irregularly marked upon the nodulose ribs with red. The sculpture consists
of about eighteen fine radiating costse, which are covered with closely arranged and rather
compressed little nodules. The intervening grooves are rather deep, somewhat narrower
than the ridges, and exhibit concentric lines of growth. The dorsal areas on both sides
of the beaks are lanceolate, smooth, and a little sunken. The beaks are about central,
slightly eroded at the extreme apex, and scarcely incline either towards the anterior or
posterior side. The dorsal margins are very slightly concave, about equal in length,
and converge at an angle of about 100 degrees. There are two unequal cardinal teeth in
each valve, and a latei-al on each side. The front cardinal in the right valve is stout,
triangular, and conical, the hinder one being much smaller, slender, and neither joined to
it, nor Teaching to the dorsal edge above. The cardinals in the left valve are very
divergent and more equal, the posterior one, on the contrary, being rather larger than
the other. The anterior lateral in the right valve, and the posterior in the left, are
separated from the outer edge by a distinct groove, which receives the marginal lateral
respectively of the opposite valve. The ligament is small, entirely internal, and placed
in a little pit beneath the apices. The muscular scars are rather large and deejD, the
anterior being longer than the posterior, which is roundish. The simple pallial line is
also distinct and rather far from the margin, which is strongly dentate, and of a double
contour, and the hinge-line between the umbones and the lateral teeth, under the
microscope, is seen to be very peculiarly corrugated.

Length 4 mm., height 3^, diameter 2|-.

Habitat. — Simon's Bay, Cape of Good Hope, in 15 to 20 fathoms.

This species is very like Carditella pallida, Smith, the type of the genus, from Port
Piosario, Patagonia. It differs in being a little more solid, has a somewhat stronger hinge,
more slendec, more numerous, and more distinctly noduled ribs.

EEPORT ON THE LAMELLIBRANCHIATA. 217

CarditeUa torresi, n. sp. (PL XV. figs. 8-8a).

Testa parva, inajquilateralis, eonlata, alhida, rufu sparsim uotata, costis radiantiltus
tc'iiuibus (juiudcuis pulcherrime .s(|iiainulatis instructa. Lunula cordata, kevis, profunda ;
area dorsalis postica angusta, lanceolata, Ifevis, subprofunda. Margo dorsi posticus paulo
obli(iUus, rectus, anticus l)revior, concavus, lunida convexa interruptus. Latus anticiim
angustum, obtuse .sul)angulatuni, postieum subtruncatum. Cardo ut in ConUtella
angdsi.

This pretty little species is rather convex, somewhat cordate, narrowed in front, Ijroad
and sulitruucatc behind. It is whitish and sometimes spotted more or less with red.
The sculpture consists of fifteen fine well-raised radiating ribs, which are beset with
numerous small arched scales. The interstices between the ridges are fully twice their
width, and exhibit strong wrinkled lines of growth and frequently a feeble radiating lira
on each side of the costse. The posterior dorsal slope is straight, and only a little oblique,
the anterior, on the contrary, jjeing very suddenly sloping and concave except where the
small smooth cordate lunule projects a little along its central line. The hinder slope
exhibits a narrow lanceolate smooth dorsal area which is also somewhat sunken. The
umbones are a little elevated, incurved some distance in advance of the centre, and curve
over towards the front. The ventral margin is well curved, and on each side where it
meets the dorsal slopes forms a rounded angle. The hinge is composed of a strong
central almost horizontally placed cardinal tooth in the right valve, fitting in between
two in the left, of which the anterior is small, conical, and the posterior long and
subparallel with the dorsal line. A lateral tooth is present on each side in both vah'es,
the anterior in the right and the posterior in the left being the most distinct, and
separated from the outer edge by a deep groove. The ligament is small and placed on
the hiuge-line above the posterior cardinal of the left valve. The interior is grooved, the
grooves corresponding with the external ribs, and the outer margin is strongly and
squarely dentate.

Length 5 mm., height 4;^, diameter 3f.

Habitat. — Station 188, south of New Guinea, in 28 fathoms ; also Torres Strait, in
3 to 11 fathoms.

In this species and CarditeUa aiKjasi imil CarditeUa capensis the hinge-plate between
the cardinal and lateral teeth is peculiarly striated with wrinkles.

CarditeUa ancjasi, n. sj). (PI. XV. figs. 9-9a).

Testa subquadrata, valde inasquilateralis, antice angusta, postice lata, rotuude trun-
cata, alba, supra costas rufo irregulariter maculata, costis radiantibus tenuibus nodulosis

(ZOOL. CHALL. EXP.— PART XXXV. — 1885.) ■ Mm 28

218 THE VOYAGE OF H.M.S. CHALLENGER.

circa 21 instructa; lunula cordata, rufescens, impressa. Pagiua iutcnia all)a, umbones
versus sordide fuscesceiis. Dens unicus cardinalis in valva dextra crassus, triangularis, inter
duos valvae siuistrse interpositus. Dentes laterales in utraque valva parvi, parum remoti.

This species is somewhat squai^e, narrowed and rounded in front, broad and
curvedly truncate behind. It is very inecpilateral, moderately convex, white and pro-
miscuously spotted with red upon the radiating costse which adorn the surface. These are
rather fine, about twenty-one in number, finely nodulose, and about equal in width to
the grooves between them, five or six on the upper part of the posterior end being a
trifle finer than the rest. The posterior dorsal margin is almost horizontal and straight,
the anterior, on the contrary, being very suddenly oblique and the ventral margin is
broadly curved. The lunule is small, cordate, reddish, a little sunken, and clearly
defined. The hinge consists of a strong central triangular tooth in the right valve which
fits in between two in the left. There is a distinct lateral tooth on each side in both
valves, which are about equidistant, but not very remote from the cardinals. The
interior is white, but stained with brown beneatli tlie umbones, and of course dentate at
the margin.

Length 6f mm., height 5, diameter 3f.

Habitat. — Station 163b, Port Jackson, New South Wales, in 35 fathoms; hard ground.

The ligament in this species, as well as in CarditeUa torresi, does not quite
correspond with that of the t}q)e of the genus, no portion of it apparently l)eing internal
beneath the umbones.

CarditeUa infans, n. sp. (PI. XV. figs. 10-lOa).

Testa minuta, solidiuscula, rotundata, convexa, luuulata, albida, costis circa 18 rotun-
datis, confertis, pulcherrime granulatis instructa. Lunula cordata, Isevis, in medio pro-
/ninens. Umbones paulo antemediani, incurvati, antrorsus versi. Margo dorsi posticus
decHvis, parum arcuatus, anticus subexcavatus ; margo ventris valde curvatus.

This species, though so small, apparently is adult. It is rounded with the exception
of the somewliat prominent beaks, a little inequilateral, whitish, fairly solid and convex,
and exhibits a smooth cordate lunule, which is rather prominent along the middle and
thus interrupts the otherwise concave front dorsal oblique slo^ie. The sculpture consists
of about eighteen rounded radiating ribs which are twice or three times as broad as the
narrow deep grooves between them, and are covered with closely packed transverse
tubercles. The umbones are peaked, somewliat in advance of the middle, well incurved,
and inclined over towards the front. There is a single central stronsr acute triangular
cardinal tooth in the right valve which fits in between two divergent but smaller teeth in

REPORT ON THE LAMELLIBRANCHIATA. 219

the left. The lateral teeth arc distinct on both sides, tlie anterior in the richt vnlve and
tiie posterior in the left being separated from the outer margin by a deepish groove, the
posterior in the former and the front one in the latter being, on the contrary, on the margin.
The hinge-plate between the cardinal and lateral teeth is seen under the microscope
to be finely transversely striated, and the outer margin is strongly dentate within.

Length 2f mm., height 2§, diameter 2.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

This species is remarkable for its small size and the crowded transverse tubercles on
the radiating costse, which are separated by very narrow liut deep intervening grooves.

Family C K A s s a t e l l i d .^.
Crassatella, Lamarck.

Crassatella aurora, A. Adams and Angas.

Crassatella aurora, A. Adams and Aiigas, Piiju. Zool. Soc. Loud., 1863, p. 426, pi. xxxvii. fig. 15.

Habitat. — Station 1G2, off East Moncceur Island, Bass Strait, in 38 fathoms; sand
and shells.

The types of this species, liberally presented to the British Museum by G. F. Angas,
Esq., were collected at Banks Strait, Tasmania. They are rather more finely ribbed
than would appear to be the case judging from the figure. The Challenger .specimens,
which are all smaller than the shell figured, have, however, coarser ribbing, the ribs
being attenuated laterally and scarcely reaching to the dorsal margins. The two
interrupted brownish rays appear to be a constant character, and the interior exhibit.s
more or less of a delicate rose colour. The hinge-plate on both sides of the cardinal
teeth is also rose-tinted, and the inner edsre of the valves alono- the ventral margin is
finely crenulated.

Crassatella rhomboides, n. sp. (PI. XVL figs. 1-la).

Testa compressa, quadrata, albida, vel pallide rufescens, valde insequilateralis,
concentrice subdistanter tenuiter lamellato-costata, striis micro3co])icis interruptis
concentricis undic|ue sculpta. ]\Iargo dorsi posticus subhorizontalis, rectus, elongatus,
anticus abrupte obliquus, subperpendicularis, rectilinearis. Margo ventralis vix curvatus,
dorsali postieo subparallelus. Latus anticum inferne rotunde angulatum, posticum
truncatum, supra et infra subrecte angulatum. Umbones parvi, acutissimi. ad apicem
conico-producti, partem anticam versus coUocati. Dentes cardinales graciles, elongati.
Margo valvarum internus inferne denticulatus.

•220 THE VOYAGE OF H.M.S. CHALLENGER.

Tliis species is flat, rhomboidal, very ine(|uilateral, white or pale l)rownisli and faintly
blotched with brown, concentrically finely costate, the ril:)s Ijeing sublamellar,
moderately remote, and roundly angulated at a faint raised indistinct ridge radiating
fx'om the beaks to the lower hinder extremity. The lunule is elongate, very narrow,
grooved on each side of a raised centre, and smooth. The posterior dorsal margin is almost
horizontal, straight, and longer than the anterior, which descends almost at right angles,
and is also rectilinear. The lower outline is very slightly excurved, and forms a rounded
corner at both ends. The dorsal area is linear, flat, and not aff"ected 1)y the concentric
ribs. The umbones are minute, acute, and peculiarly produced at the apex into a small
conical peak, and siti;ated a very little posterior to the anterior extremity. The two
i-ardinal teeth of the left valve are slightly divergent from one another, elongate and
slender, the anterior being a trifle the thicker, and about equal to the single tooth of the
other valve. The lateral teeth and srrooves are distinct and elongate. The outer surface
is everywhere very minutely sculptured with fine concentric striae which are broken up
1)V others that radiate from the umbones, a kind of sculpturing such as obtains in the
genus Myodora. The anterior muscular impression is elongate and subpyriform, the
posterior being rather larger and rounder. The interior is minutely denticulate along
the ventral margin, but smooth elsewhere.

Length 8 mm., height 6, diameter 2^.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; also Station 187, near
Cape York, North Australia, in G fathoms.

This is a pretty little species resembling externally the genus Myodora both as
regai'ds form and sculpture, but having the dentition and non-sinuatcd pallial line of
CrassateUa. This, togetlier with Crassatella aurora, belong to what 1 think is an
unnecessary subgenus [Crassatina) proposed by WeinkaufF, which is distinguished from
the typical Crassatella only by having the inner edge of the valves crenulated.

Crassatella parva (C. B. Adams).

Gduklia parva, C. B. Adams, Proc. Best. Soc. Nat. Hist., 184.5, p. 9.

Astarte Imiulata, Conrad, Amer. Journ. Sci. and Art.«, 18tG, vol. ii. p. 393.

Crassatella guadaloupensis, d'Orbigny, in Sagra's Hist. Cuba, vol. ii. p. 289, pi xxvii.

figs. 24-26.
Gouldia giuidaloupensis, H. and A. Adams, Genera Moll., vol. ii. p. 485.
Astarte madracea, Linsley, Amer. Journ. Sci. and Arts, vol. xlviii. p. 27.5 (woodcut).
Gouldia mactracea, Gould, Invert. Ma.ss., ed. 2, 1870, p. 128, tig. 442.
Astaiie pifeifferi, Pbilijipi, Zeitscbr. Malakozool, 1848, vol v. p. 133.
Goiddia pfeifferi, Tryon, Proc. Acad. Nat. Sci. Pbilad., 1872, p. 249.

Habitat. — Station 24, ofi" Culebra Island, West Indies, in 390 fathoms; Pteropod
ooze.

REPORT ON THE LAMELLIBRANCHIATA. 221

The form of this species is very variable, Imt tlie eonceiitrie ril)])in<; nnd mi('roseo])ie
sculpture appears to be fairly constant.

In the Proceedings of the Zoological Society, 1881, p. 490, I gave 1841 as the
(late of publication of d'Orbigny's Crassatella guadaloupensis. This, as pointed out l)y
Mr. Dall,' appears to be incorrect. At the time I did not consult the work itself but
referred to Moquin-Tandon's list of authors and their works, at the end of the fii'st
volume of his Hist. Nat. Moll. terr. et fluv. de France. The j'ear 1841 is there quoted
for the issue of Sagra's Histoire de Cuba. Mr. Dall takes the first of the two species of
Gouldia described by Professor C. B. Adams as the type of the genus. On the contrary, I
think that the second species, Gouldia parva, 8\\.0Vi\(\ be retained as the type, for this
reason, that its adoption was confirmed by Adams himself when he descrilied another
species, Gouldia pacijica, belonging to the same Crassatelloid group. Notwithstanding
Mr. Dall's dissertation on this genus, I still maintain that Gouldia is unnecessary, an
opinion also shared by Mr. Boog Watson.'^

Mr. Dall observes that there are "abundant reasons" for separating Goxddia [cerina)
from Circe " on conchological grounds alone." It is unfortunate that he does not point
out a few of them, for, as far as I can discover from his observations, there seems to be
only one difference, that of sculpture.

If difference of sculpture alone is to be held of generic importance, I think I may
fairly say that the genera of MoUusca might at once be doubled or trebled in number.
On that principle Conns cancellatus, with its strongly ridged surface, and Conus
marmorens, which is smooth, belong to different genera, Nassa glans and Nassa jxipillosa
are not congeneric, and so on in innumeral»le instances.

A few words on the variation of sculpture in the genus C/rce may not l)e out of
place. Circe scripta, the type of the genus, is a flat, concentrically ridged shell with a
little radiating sculpture at the sides near the beaks. Circe albida is equally flat and
concentrically ribljcd with only the slightest trace of the lateral oblique sculpture.
Circe divaricata is more convex, finely concentrically ridged and ornamented all
over the surface with divaricate sculpture. Circe dispar is also convex, con-
centrically ridged, but with less ol»lic[ue sculpture. Circe lentiginosa is etpially
swollen as the last species, concentrically ridged, Init withinit the diverging ornamenta-
tion. Circe castrensis is also gibbous, more or less concentrically ridged, and is
painted with angular markings as in Circe scripta. Circe trimaculata and Circe
ccrina {Gouldia, part, C. B. Adams), are gibbous, finely concentrically ridged
throughout, but without angular markings. Many more forms might be mentioned,
which would be intermediate in respect of sculpture 1)etween some of those species
which I have referred to. Anyone therefore, wlm will place side by side
Circe scripta, Circe albida, Circe divaricata, Circe dispar, Circe lentiginosa,

1 Bull. Mus. Cnmp. Zool, vol. ix , No. 2, p. 128. '■^ Jouni. Coiicbol., vol. iii. p. 299.

222 THE VOYAGE OF H.M.S. CHALLENGER.

Circe castrensis, Circe trimaculata, and Circe cerina, will, I think, perceive the
gradual transition of one form into the other, and will be convinced that neither
Lioconcha nor Gouldia (as understood by Dall) should take generic if even subgeneric
rank.

Mr. Dall states that " we do not know the animal of Circe." This is not correct, for
Deshayes (Proc. Zool. Soc. Lond., 1853, p. 171) has examined the soft parts of several
species belonging to the two principal groups of the genus "[Circe scripta, Linn., and
Circe testudinalis, Chemn.)," and figures the animal of Circe divaiicata. He observes
that " ces animaux ne different en rien de celui des Meretrix " and " de cette ideutite,
parfaitement constatee pour nous, entre les Meretrix et les Circe, nous concluons que ce
dernier genre doit rentrer dans le j)remier a titre de simple division ; en reuuissant les
especes des deux groupes on voit s'etablir entre elles one transition insensible dans la
transformation de formes exterieures."

Romer, in his monograph of the genus Vcnu.^, regards Lioconcha as a " sectio " of
Cijtlierea, which is termed by him merely a subgenus of Ve)i us. Circe he also considers
a section in the same way.

Gouldia parva, which I hold as the type of the genus, is considered by Dall to belong
to Eriphyla of Gabb, which is stated l)y Dall to 1je a subgenus or section of Crassatella.
This location of Erip)hijla cannot, however, be correct, if Gabb's description is to be
relied upon, for, besides an external ligament, that genus apparently has a different
hinge, and according to Stoliczka partakes more of the general character of certain forms
of Veneridse. Dall says that Gouldia parva and the like " differ from the typical
Crassatella chiefly in form, in the elongation and more distant location of the lateral
teeth, the usually unequal valves, and in their uniformly small size." Now, of these
points of distinction, I maintain that form and size are not generic or even subgeneric
characters, the inec[uality of the valves I fail to discover in the series of specimens in the
British Museum, and the difference mentioned in regard to the lateral teeth does not
appear to me to exist. In Crastsatella hingicola, which may be regarded as a typical
species, 1 find the posterior lateral teeth and those less pronounced on the anterior side,
extending from the upper end of the muscular impressions towards the umbones. This
too is constant in all the other species of the genus which I have examined, including that
under discussion, Crassatella parva of C. B. Adams. To show the absolute agreement of
this form with Crassatella, I would point out two minor features which I believe have not
as yet been referred to, namely, the coarsely striated character of the cardinal teeth and
the presence of a small deep distinct pedal muscular scar just above the anterior
adductor impression.

A summary of the whole discussion and difference of opinion may be given in a few
words.

I regard Goiddia parva as the typical species ; Dall holds to Gouldia cerina. \

REPORT ON THE liAMELLlBRANCHIATA. 223

maintain that the former species is absohxtcly ideuti(';il with Crassatella, hence the
disappearance of (Touldla from conchology. Dall holds tluit the hitter species is
generically distinct from Circe " on conchological grounds alone." This I deny, and am
of opinion that it possesses at most sectional or subgeueric rank, and may therefore be
placed in Lioconcha if this separation be thought advisal)le. To give names to such
minor sections, if they be fiiirly recognisable, is 1 think alIowal)le, and to a certain
extent useful in those genera which contiiin a large numl)('r of species, but in sninll
groups this practice should not Ix' encouraged.

Crassatella torresi, n. sp. (PI. XVI. figs. 2-2a).

Testa parva, valde compressa, tenuis, alba, trigona, costis concentricis paucis postice
incrassatis et productis instructa. Margines dorsi valde declives, fere sequales, antico
levissime concavo, postico vix convexo ; margo ventralis maxim e curvatus. Umbones
parvi acuti, mediani. Dens cardinalis unicus in valva dextra, duo in sinistra ; laterales
utrinque perremoti. Ligamentum angustum, in sulco marginali locatum, partim
internum, in fossa parva. infra apices positum.

This little species is very compressed, equilateral, quadrant-shaped, thin, semi-
transparent, white, and ornamented with about a dozen rather remote concentric ridges.
They are thickened at their posterior extremities and a trifle prolonged into scale-like
projections, forming a crest along the dorsal margin. Between the costse very fine
radiating striaj are discernible under the microscope. The dorsal margins are of equal
length, and form almost a right angle at the apex. The anterior is the least concave, and
the posterior the slightest excurved. There is a single central longish cardinal tooth in
the right valve, which fits in between two equally long ones (of which the posterior is
rather the larger) in the left, and the former valve exhibits a distinct very remote lateral
on each side, separated from the outer margin by a conspicuous furrow which receives
the prominent lateral margins of the other valve. The slender ligament is situated in a
narrow posterior marginal groove, and a small portion of it is internal and located in a
very small pit Ijeneath the beaks and just posterior to the cardinal teeth. The interior of
the valves is smooth and glossy, and owing to their trans^^arency exhibits the external
ribbing. The outer margin is simple, smooth, and non-creuate. The muscular scars
and pallial line are not clearly definite.

Length 3^ mm., height 3^, diameter 1.

Habitat. — Station 188. south of New Guinea, in 28 fothoms green mud.

The single minute shell here characterised may not be, and probably is not, adult, but
is sufficiently distinct and pecidiar to merit description.

224 THE VOYAGE OF H.M.S. CHALLENGER.

Famil}' T r i g o N 1 1 d ^.

Trigonia, Bruguiere.
Trigonia lamarckii, Gray.

Trigonia lamarckii, Gray, Anu. and Mag. Nat. Hist., 1838, p. 482.

Trigonia lamarckii, A. Adams, Proo. Zool. Soc. Lond., 1849, p. 159.

Trigonia lamarcliii, Reeve, Concli. Icon., vol. xii. figs, la-lf.

Trigonia lamarckii, var. reticulafa, Tenison-Woods, Proc. Linn. Soc. N. S. Wales, 1877,

vol. ii. p. 125.
Tngunia pedinata, (non Lamarck) Stutelibur}', Zool. Journ., vol. v. p. 97, Tab. Suppl. xlii.
Trigonia peel inata, Canefri, Viagg. Magenta, p. 137.

Habitat. — Port Jackson, Sydney, in 2 tn 10 fathoms.

I would here remark that Trigonia jukesii, A. Adams, is identical with Trigonia
uniophora, Gray, and quite distinct from the present species, to which it is united
by Eeeve.

Trigonia margaritacea , Lamarck.

Trigonia margaritacea, Lamarclv, Anu. du Mus., 1804, vol. iv. p. 355, pi. Ixvii. fig. 2.

Trigonia margaritacea, Sowerby, G6n. of Shells, pi. Ixxxiv. figs. 1, 2.

Trigonia margaritacea, H. and A. Adams, Gen. Moll., pl. cxxiv. figs. 1-1//.

Trigonia margaritacea. Reeve, Conch. Icon., vol. xii. figs. 3a-dcl.

Trigonia margaritacea, Huxley, Proc. Zool. Soc. Lond., 1849, p. 31, pl. iii. figs. 1-3 (animal).

Trigonia margaritacea, Huxley, Ann. and Mag. Nat. Hist. 1850, vol. v. p. 141.

Trigonia margaritacea (fj, Selenka, Mai. Blat., 1868, vol. xv. \\. 66, pis. ii. and iii.

Trigonia jKctinata, Lamarck, Anim. sans vert., cd. 2, vol. vi. p. 514.

CJiama pcctinata, Wood, Index Test. SuppL, pl. ii. fig. 6.

Habitat. — Station 162, off East Moncteur Island, Bass Strait, at a depth of 38
fathoms ; sand and shells.

This species is also found at Port Lincoln, South Australia, the variety from that
region having the tuljercles on the ridges very much crowded.

Trigonia uniophora. Gray.

Trigonia uniopliora, Gray, Jukes' Voy. of the "Fly" (1847), vol. ii.. Appendix, p. 361, pl.

ii. fig. 5.
Trigonia nnioplwra, Eeeve, Couch. Icon., vol. xii. i>l. i. figs. 2a, 2''.
Trigonia jukesii, A. Adams, Proc. Zool. Soc. Lond., 1849, p. 159, pl. iii. figs. 4-6.

Habitat. — Near Cape York, off Albany Island, in :^ to 12 fathoms ; Stations 188 and
189, south of New Guinea, in 25 to 28 fathoms.

REPORT ON THE LAMELLIBRANCIJIATA. 225

This species is quite distinct from Trigonia lamarckii from. Port Jackson, difteriug
.not only in sculpture but also in form, the emargination of the posterior truncated side
being constai.t in a'l specimens. It is only known at present as an inhabitant of the
region between North Australia and New Guinea.

Family N u c u l i d .^i;.

Nucithi, Lamnrck.
Nucida obliqua, Lamarck.

Nucula ohliqua, Lamarck, Hist. Nat. Anim. sans vert., ed. 2, vol. vi. p. 505.
Nucula ohliqua, Hanlcy, in Sowerby's Thes. Couch., vol. iii. p. 156, pi. ccxxx. fig. 150.
Nucula ohliqua, Chenn, Manuel Conch., vol. ii. p. 179, fig. 897, from type teste Hauley.
(Non Nucula ohliqua, Sowerby, Conch. 111., fig. 21 ; and Hanley, Cat. Recent Biv. Shells,
p. 171, pi. XX. fig. 9 = Nuetila grarji, d'Orbigny.)

Habitat. — Station 188, south of New Guinea, at a depth of 28 fathoms; also
Torres Strait, 3 to 11 fathoms (Challenger); Arafura Sea, North Australia, 32 to
36 fathoms (Dr. Coppinger of H.M.S. "Alert") ; Cap aux Iluitres, Australia (Peron teste
Lamarck).

This appears to be the largest living species of the genus Nucula. A single valve from
the Arafura Sea collected by Dr. Coppinger is 28 mm. in length and 20 high. At this
age it is a strong solid shell, internally thickened along the ventral margin, having deep
muscular impressions. The hinge-teeth are long, acute, keeled on the sides towards the
umboues, and excavated exteriorly. In the largest specimen there are twenty-six on the
anterior margin and only seven posteriorly, and in another example of half the length
there are twenty in front and five behind. The ligament-pit is horizontal, deep, and
narrow. The internal nacre is whitish, or tinted with pale brown or red. The
excessively fine crenulation of the margin described by Hanley is preserved in the oldest
specimens.

Nucula nitidula, A. Adams.

Nucula nitidula, A. Adams, Proc. Zool. Soc. Lond., 1856, p. 51.

Nucula nitidula, Hanley, in Sowerby's The-. Conch., vol. iii. p. 150, pi. ccxsix. tig. 142.

Nucula nitidula, Sovrerby, Conch. Icon., vol. xviii. pi. iv. fig. 27.

Nucula nitirhda, Huttun, !Man. New Zeal. Moll., p. 16t.

Habitat. — Station 167a, Queen Charlotte Sound, Cook Strait, New Zealand, in 10
fathoms ; mud.

This species is remarkable for its oblique narrow form, the almost rectilinear or very
slightly curved hinder dorsal slope, and its prominent defined lunular space.

(zool. CH.\LL. EXP. — PART XXXV. — 1885.) Mm 29

220 THE VOYAGE OF H.M.S. CHALLENGER.

Nucvla sp.

Habitat. — Station 191, off the Arrou Islands, in 800 fathoms; green mud.

Only a single dead valve of this species was discovered, and that not in a good state
of preservation. Its existence is worthy of record, as indicating the presence at this
locality of a large species which in many respects closely resembles the Nucula
decussata of Europe. It is perhaps a trifle flatter than that form, and tlie anterior side
in the region of the hmule is rather more concave, but the external sculpture is about
the same. The hinge-plate and the teeth appear to be less strongly developed, and tln'
outer or ventral margin is not quite so distinctly lirate within.

The valve under examination is 22 mm. in length and 18^ in height.

Nucula niponica, n. sp. (PI. XYIII. figs. 8-8«).

Testa magna, tenuis, ovalis, valde insequilateralis, epidermide nitida olivacea induta,
incremeuti lineis tenuibus striata, lineis paucis radiantibus obsoletis impressa. Lunula
inconspicua, imjjressione hand profunda circumdata. Umboues pallidi, couvoluti, circa
in \ longitudinis totius positi. Pagina interna iridescens, cseruleo-margaritacea,
radiatim tenuissime substriata, ad niarginem acuta et Integra. Fossa ligamenti profuoda,
intra vulvas oblique projecta. Dentes elongati, acuti, in numero circa 25, quorum octo
ante umbones sunt.

This is a fine large species, comparatively thin, of an oval form, the anterior extremity
being just a trifle more acute than the j)osterior. It is very inequilateral, and clothed
with a highly glossy olivaceous epidermis, which is paler towards the umbones, and
exhibits, at irregular intervals, narrow, concentric, darker zones. The sculpture consists
of fine lines of growth (some of them amounting to shallow concentric grooves) and
several feebly expressed radiating impressed lines. The lunule is rather long,
prominent along the middle, not clearly defined, but only marked ofi" by a shallow
depression, and occupies the greater part of the anterior slope. The beaks are pale,
small, incurved, and located at barely one-fourth of the total length from the anterior
end. The interior is iridescent pearly, the predominant colour being blue. It exhibits a
very minute radiating substriation, and is surrounded by a sharp, simple, non-crenate
edge. The hinge-teeth are fairly strong, longish, acute, about twenty-five in number, of
which only eight are in front of the deep, oblique, inwardly projecting ligament-j)it.

Length 22 mm., height 15, diameter 9.

Habitat. — Station 232, south of the Island of Nipon, Japan, in 345 fathoms ; green
mud.

EEPORT ON THE LAMELL1J5RANCHTATA. 227

Nucida torresi, n. sp. (PI. XVIIl. figs. 9-9a).

Testa parva, solidiuscula, triangularis, paulo inajquilateralis. convexa, albido-fnsccsccns,
epiderinide 1 induta, eostulis tenuibus concentricis iustructa, radiatimque striata.

Lunula magna, in medio prominens, impressione baud profunda circumscri])ta. ]\Iargo
dorsi utrinque vix excurvus ; posticus paulo magis elongatus, sed minus obliquus.
Pagina interna albo-margaritacea, margine inferiore intus minute crenulato. Denies ad
quatuordecim fortiusculi, props medium seriei fossa parva ligamenti intcrrupti.

This is rather solid for so small a species, a little unequal-sided (tlio anterior end
being the shorter), of a triangular form, bluntly angled at the anterior end, ;ind rather
more rounded behind. It is considerably convex, of a whitish brown colour, and, in a
dead condition (the few valves preserved are in this state), presents no trace of an
epidermis. The sculpture consists of numerous concentric riblets, which are attenuated
at the sides, and exhibit, principally in the intervening grooves, fine radiating striic.
The dorsal margins converge almost to a right angle, and are scarcelj^ at all excurved,
the anterior being shorter and more oblique than the posterior, and faintly bulged bj"
the central line of the large lunule, which is marked off by a shallow depression. The
umbones are rather blunt, but incurved at the small tip and decidedly in front of the
centre. The interior is thickened, pearly white, and minutely crenulated along the
lower border. The hinge-plate is strong, and sup)ports about fourteen teeth, of which
six are usually in front of the small non-projecting ligamental pit.

Length 2fmm., height 2|, diameter 2.

Habitat. — Station 185, east of Cape York, North Australia, in 135 f\ithoms ; coral sand.

This species is remarkable for its solidity, its comparative e(pial-sidedness, and the
strong character of the concentric sculpture.

Nvcula 2^ernamhi(censis, n. sp. (PI. XVIII. figs 10-10«).

Testa irregulariter quadrate ovata, modice convexa, insequilateralis, eoncentrice
tenuiter sulcata et lirata, alba, nitida. Umbones antemediani, paulo supra marginem
dorsalem producti. Linea cardinis mediocriter fortis, dentibus ad decem in.structa.

This species is longer than high, irregularly squarely ovate, moderately convex,
somewhat inequilateral, white, glossy, and sculptured with regular, fine, concentric
grooves, and intervening lir^e, except upon and towards the smooth apices. The lunule
and dorsal area are not defined. The posterior dorsal margin rises higher, and is longer,
than the anterior, which, however, is more sloping. The ventral outline is widely
arcuate, and forms with the hinder lateral margin a rather more sharply rounded
extremity than in front. The beaks, viewed from the side, are somewhat obtuse,

228 THE VOYAGE OF H.M.S. CHALLENGEE.

incurved at the tips, ;iiid situated consideraMy iu front of the middle. Tlie interior i.s
pearly white, and the inner edge of the valves smooth. The hinge-plate is moderately
strong, and furnished with ten or eleven stoutish teeth, six of which on the posterior
side are larger than the four or five on the opposite margin.

Length 3 mm., height 2^, diameter 1

Habitat. — Station 120, off Peruamhuco, Brazil, in 675 fathoms; red mud.

The few small valves here described bear considerable resemblance to Niicula corhii-
loides of Seguenza, a Tertiary fossil from Italy, but are, I believe, distinct ; for, besides a
difierence in form, the surface cannot be described as " Isevis, lineis incrementi paucis
siguata" (Seguenza), the concentric strias in the present species being regular, numerous,
and even strong for so small a shell.

Nucula culebrensis, n. sp. (PI. XVIII. figs. 11-11(().

Testa subcompressa, medioeriter crassa, valde incequilateralis, ovato-trigoua, con-
centrice tenuissimc lirata, uudique radiatim striata, postice serie arcuata jirope marginem
dorsalem tuberculorum compressorum in utraque valva ornata. Margo dorsi posticus
elongatus, declivis, subrectus, anticus brevior, vix excavatus. Lunula et area postica
distinctse. Dentes cardinis eirciter vio'inti. Pamna interna alljo-marjxaritacea, marffine
inferiori intus tenuiter crenulato.

This species is ovately trigonal, sharply rounded at each end, rather compressed, very
inequilateral and moderately solid. It is sculptured with numerous fine concentric
liree and closely packed minute radiating strije, chiefly visible in the intervening grooves,
and near the posterior dorsal margin in both valves some of the concentric lir£e are
thickened at the ends, forming a series of compressed tubercles, which mark ofi" a smooth,
lanceolate, posterior area. The dorsal margins meet almost at a I'ight angle, the posterior
being nearly straight, and the anterior also straight or very slightly concave. The
ventral margin is gently curved. The umbones are small and curved over towards the
front over an indistinct, small lunule, beyond which a faint groove radiates from the
beaks to the anterior extremity. The hinge-teeth are moderately strong, about twenty
in number, of which seven or eight are in front of the beaks and the rest behind. The
interior is pearly white, and the lower margin is minutely crenate within.

Length 6 mm., height 5, diameter 3^.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

Only dead white valves were obtained, so it is impossible to describe the ej^idermis,
which, however, in all probability, was of an ordinary character. The chief characters
of this species are the concentric lirse, the radiating striae, and the tubercles down the
posterior slopes.

REPORT ON THE LAMELLIBRANCHIATA. 229

Nucula unnjimyensis, Suiitli (I'l. XVIII. figs. \2-V2h).

Niirvla itrgxaijensis, Smith, Ann. ami Mag. Nat. Hi.sl., 1880, .ser. .5, vol. vi. p. 320.

Habitat. — Station 321, oli' Monte Video, at the moiitli of the Kio de La Plata, in 13
fathoms ; mud.

In describing this species I followed Hauley, whose excellent monograph of the
Nuculidse I then consulted, in regarding the longer side anterior, and that towards which
the beaks incline posterior, which is the reverse of what has been done in the descriptions
in this Report. The six specimens obtained by the Challenger are adult, and show that
the species is constant in form and general facies. They are of the same olivaceous tint
as the type, but exhibit at intervals rather more distinctly a few darker concentric zones
where the valves are somewhat deeply furrowed at periods of arrested growth.

Nucula reticulata, Jeffreys.

Nucula reticulata, Jeffreys, Anu. and Mag. Nat. Hist., 187G, ser. 4, vol. xviii. p. 429.
Nucula reticulata, JefEreys, Proc. Zool. Soc. Loud., 1879, p. 583, pi. xlvi. fig. 7.

Habitat. — Station 78, off' San Miguel, Azores, in 1000 fathoms; volcanic mud.

It is on the authority of Dr. Gwyn Jeffreys, who has examined the few valves from
this locality, and referred to them in the latter of the above works, that I designate these
with this name, for I have not seen the types procured by the " Valorous " expedition.
They agree very fairly with his description, but are more angular in front than the
figure, of whicli the anterior margins do not slo^ic to " a rather sharp point."

Nucula ^yrofundorum, n. sp. (PI. XVIII. figs. 13-1 3a).

Testa rotuudata, paulo iuEequilateralis, modice convexa, pallide flavescens, uitida,
tenuissime radiatim substriata, ad apicem marginemque inferiorem versus Itevis. Linea
cardinis fortiuscula, dentibus undenis in valva dextra novenisque in sinistra instructa.
Pagina interna radiatim tenuissime lineata, margine externo minute lirato-dentieulato
circumdata.

Length 3 mm., height 2^, diameter If.

Habitat. — Station 24G, Mid North Pacific, in 2050 fathoms ; Globigerina ooze.

This species is very like the Atlantic Nxicula reticulata, Jeffreys, but may, I think,
be separated. It is perhaps a little rounder, slightly more equilateral, and much more
finely striated, indeed, the striae should rather be described as hair-like whitish lines.

230 THE VOYAGE OF H.M.S. CHALLENGER.

Nucula (Acila) niirahilis, A. Adams and Eeeve.

Nueula mirahilis, A. Adams and Keove, Zool. Voy. " Samarang," p. 75, pi. xxi. fig. 8.
NiiniJa mirahilis, Hanley, in Sowerby's Tbes. Coneli., vol. iii. p. l.^r), pi. coxxis. fig. 114.
NiLcula mirahilis, Dunker, ludex Moll. Japon., p. 238.
Nucula {Acila) mirahilis, H. and A. Adams, Gen. Moll., ii. p. 545.

Habitat. — Station 233a, off Kobe, Japan, in 8 to 50 fathoms (Challenger) ; Kieu-
sieu, Nagasaki Bay (Adams ;ind Ree\'e).

The single shell from Kobe is exceptionally large, being 30 mm. long and 21 iu
height.

Nucutina, d'Orbiguy.

Nuculina oralis (S. Wood) (PI. XIX. figs. l-\h).

Pleu.radon ovalis, S. Wood, Ann. and Mag. Nat. Hist., 1840, vol. iv. p. 230, pi. xiii. fig. 1.
NiicineUa miliaris, (Deshayes?) S. Wood, Monog. Crag Moll., vol. ii. p. 73, pi. x. figs. 4, a-c.

Testa parva, insequilateralis, altior quam longa, irregulariter oblique ovata, solidiuscula,
alba, Isevis, striis incrementi sculpta. Margo dorsi infra uraboues subhorizontalis, brevis,
parum arcuatus. Latus anticum paulo supra medium angulatum, supra angulum obliquum,
rectiusculum vel incurvatum, infra id leviter curvatum ; postieum latissime areuatum ;
inferius paulo excurvatum. Cardo validus, dentibus primariis 7-8 insequalibus, in
valva sinistra, lateralique elongato postico lamelliformi iustructus. Pagina interna baud
margaritacea, subnitida, cicatrice postica maxima notata, margine simplice, baud crenulato
•circumdata.

This little species is much higher than long, somewhat obliquely and irregularly
ovate, moderately strong, not particularly convex, white, smooth, and sculptured with
fine lines of growth. It is a trifle inequilateral, the umbones being located just a little
behind the centre. The front side margin is at the upper part oblique, and almost
straight, or even very faintly incurved, then rather suddenly angulated, the angle falling
a little above the middle, beneath which it exhibits a faint curve. The posterior side
forms one regular very gentle arcuation, and the basal outline is only a little more
rounded. The hinge-plate is broad and in the left valve armed with seven or eight
primary teeth, of wliich two anterior and three posterior are somewhat stronger than
those intervening. They are prominent, pointed, separated by deep pits, and arranged
in a slightly curved series. The lateral tooth on the posterior side is long and thin, and
separated from the outer margin by a deep groove. The interior of the valves does not
appear to be highly glossy or pearly, is smooth at the margin, and slightly thickened just
within. The posterior muscular impression is remarkably large and situated low down
beyond the lateral tooth.

Length 2^ mm., height 3^, probable diameter If.

IIEFORT ON THE LAMELLIBRANCHIATA. 231

Habitat. — Simon's Bay, Cape of Good Hope, in 15 to 20 fathoms.

The above description is based upon the specimens obtained by the Challenger.

This is the first record, I believe, of the existence in a living state of this most interest-
ing species. The genus is already known as recent, one species from the Catalina Islands
having been described by Carpenter as NucuUna munita, and another from the Korean
Straits by A. Adams under the name of Huxleyia sulcata.

Only three left valves of this species were obtained. They differ from Crag
specimens in being larger, and consequently appear rather higher, as, with the growth of
the shell, the height increases more than the length. The hinge-teeth are precisely the
same in some of the fossil specimens, but usually appear to be somewhat fewer.

I am not quite convinced that the Nucula miUaris of Deshayes, from the Paris Basin,
is the same species as the Crag shell. There appear to be certain differences in form, in
the somewhat pearly interior and position of the ligament w^hich distinguish the former.

Mr Searles Wood ^ does not assign any reason for abolishing his name Pleurodon and
substituting for it that of Nucinella. It may have been that he found that the appella-
tion Pleurodonta- had previously been employed in the Mollusca, and in his judgment
that it too closely resembled the genus created by himself. Be that as it may, I do not
think he was justified in assigning a new name to this genus, seeing that d'Orbigny in
the meantime had suggested that of Nuculina.^

Leda, Schumacher.

Leda semen, n. s}). (PL XIX. figs. 2-2a).

Testa minuta, couvexa, inajquilatcralis, oljlouga, antice acute rotundata, postice
breviter rostrata, extremitatem versus radiatim impressa, incrementi lineis tenuiter
striata, sordide albida. Margo dorsi anticus elougatus, leviter convexus et declivis,
posticus brevior, primo rectiusculus, dein ad extremitatem curvatus. Margo inferior late
arcuatus, postice leviter sinuatus. Umbones aliquanto prominentes, involuti, postice
inelinati, postmediani. Linea cardinis mediocriter valida, deutibus novenis posterioribus.
duodcnisque anterioribus instructa. Fossa ligamenti triangularis, profunda.

This very small species is fairly solid, very inequilateral, elongate, sharply rounded at
the anterior end and shortly beaked behind, the point, however, not being very acute.
The valves exhibit a broad shallow depression down the posterior side, which causes, at
that part, a faint sinuation in the otherwise regularly and broadly curved lower outline.
The dorsal margin is oblique on both sides, slightly excurved in front, straightish at first
behind, and then curving downwards to the extremity. The sculpture consists of very
iine lines of growth only. The beaks are a little prominent, curve inwards towards one

' Monog. Craj; Moll., vol. ii. p. 72 (1852-55). - Fischer de Waldlicim Mus. Doiuidof., iii. (1807).

3 Paliont. Frang. Terr. Cret., t. iii. p. 161 (1843).

232 THE VOYAGE OF H.M.S. CHALLENGER.

another, and have a posterior inclination. The hinge-plate is moderately strong, and
furnished with al)out twenty-one teeth, of which about nine are in front of the small deep
ligamental pit and twelve hehinu it. The interior is glossy, and the scars and pallial
impression are not clear.

Length 3 mm., height 2, diameter l^.

Habitat. — Station 122, off Pernambuco, Brazil, in 350 fathoms; red mud.

Although so small, the shells here described appear to be adult. They are devoid
of an)^ special striking feature, but are peculiarly contracted and beaked at the
posterior end.

Leda excisa (Philippi).

Nuciiln excisa, Philippi, Enum. Moll. Sieil., vol. ii. p. 46, pi. .\.v'. fig. 4.

Malletia excisa, Jeffreys, Proc. Zool. Soc. Lend., 1879, p. 586.^

Mallet ia excisa, Jeffre3s, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 435.

Habitat. — Station 70, west of the Azores, in 1675 fathoms; Globigerina ooze.

The sinus in the posterior side is not quite so marked in the two valves from this
Station as in Philippi's figure.

Althongh stated to be wholly external by Jeffreys, I am of opinion that the valves
are also connected by an internal cartilage, because I find a minute pit for its reception
as in other species of Leda immediately under the apex of the umbones, and consequently
have placed it in that genus.

Leda decipiens, n. sji. (PI. XIX. figs. 3-3a).

Testa convexa, insequilateralis, oblonga, antice angusta, acute rotundata, postice
insigniter dilatata, qnadrate oblique truncata et concave impressa, liris tenuibus numerosis
regularibus oruata. Margo dorsi anticns leviter declivis, fere rectus, posticus longior,
horizontalis, rectilinearis aut vix incurvatus. Margo ventris late arcuatus, antice lente
adscendens, post medium maxime prominens. Umbones parvi, antemediani, Iseves.
Linea cardinalis subcrassa, lata, dentibus circiter trigiuta instructa. Lunula angusta,
paulo impressa. Area posterior latior, profunda, acute marginata.

Length 10 mm., height 7, diameter 5i.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

The .slight broad depression down the posterior side causes the fine concentric lirse to
be the least flexuose at that part, and the truncation consequently is not absolutely
rectilinear. Of the thirty teeth about seventeen are posterior and thirteen anterior.
The muscular scars and pallial line are not sufficiently clear for description.

REPORT ON THE LAMELLIBRANCHIATA. 233

This species has very much the form of Nucula dilatata, Philippi, a Sicilian
Tertiary fossil, but appears to be more solid, more strongly striated, and has a well-
marked doz'sal area, and the posterior dilated side is not so perpendicularly truncate.

Leda inaudax, n. sp (PL XIX. figs. 4-4a).

Testa minuta, couvexa, solida, triangulariter ovata, antice rodundata, postice euneata,
alba, concentrice tenuiter et regulariter lirata. Margo dorsi utrinque sequaliter valde
declivis, antice vix excurvatus, postice in medio leviter concavus. Margo inferior late
arcuatus, postice haud sinuatus. Umbones rotundati, paulo antemediani, incurvati,
postice iuclinati. Linea cardinis fortis, dentibus circiter octo utrinque instructa.

Length 2^ mm., height If, diameter 1^.

Habitat. — Station 24, ofi" Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

Although narrowed behind, this little shell has not a rostrate aspect, there being no
incurvation of the ventral outline near the posterior extremity which is roundly
pointed. Neither is there any radiating depression as in some allied forms, and the
concentric lir'se are fine and regular.

Leda conftnis, n. sp. (PI. XIX. figs. 5-5a).

Testa parva, solida, convexa, ovata, postice acuminata, breviter rostrata, impressionem
radiantem latam exhiliens. Valvae nitidse, flavescentes, incrementi lineis tenuissimis
striatse. Margo dorsi anticus declivis, arcuatus, posticus primo rectiusculus, obliquus,
dein magis descendens. Margo inferior late curvatus, prope extremitatem posticam haud
profunde sinuatus. Umbones subpellucidi, postice inclinati. Dentes fortes circiter
18-20 linea cardinali forti dispositi.

Length 3g mm., height 2^, diameter If.

Habitat. — Station 78, off the Azores, in 1000 fathoms ; volcanic mud.

This species bears considerable resemblance to Leda messanensis, but does not attain
so large a size. It is proportionally thicker,* more convex, more inequilateral, the
posterior end being considerably smaller than the anterior, which is rather less acutely
rounded.

Leda solidula, n. sp. (PI. XIX. figs. G-Ga).

Testa subtriangulariter ovata, postice acute sed breviter rostrata, solida, convexi-
uscula, sequilateralis, nitida, albida, concentrice subfortiter lirata, liris utrinque attenuatis

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 30

234 THE VOYAGE OF H.M.S. CHALLENGER.

fere obsoletis. Margo dorsi anticus rectiusculus, cleclivis, posticus paulo magis obliquus,
levissime excurvatus. Margo inferior antice inque medio arcuatus, propc extremitatem
posticam ad terminum impressionis late ab umbone radiantis conspicue sinuatus. Area
dorsi postica lata, porca rotundata marginata, prope medium porcam parvam mimi.s
conspicuam exhibens. Linea cardiuis crassa dentibus ad 20 elongatis acutis muuita.

This small species is about equilateral, ovate-triangular, rounded in front and acutely
peaked behind. It is rather convex and solid, exhibits a shallow radiating depression
down the posterior side, is whitish, glossy, and sculptured with rather strong concentric
lirge which are attenuated and somewhat obsolete on both sides. The front dorsal margin
is straightish and moderately oblique, the posterior a trifle more sloping and very faintly
excurved, and the lower outline is gently convex in front and at the middle, but
conspicuously sinuated at the beaked end. The hinge-plate is strong, and armed with
about twenty long, sharp teeth, of which there are one or two more behind the cartilage-
pit than in front.

Length A^ mm., height 3, supjjosed diameter of perfect shell 2^.

Habitat. — Station 120, off Pernambuco, in 675 fathoms; red mud.

I have ventured to describe this species from a single valve only, as its form is
peculiar, and the sculpture well marked.

Leda jeffreysi, Hidalgo.

Leda lata, Jeffreys, Ann. and Mag. Nat. Hist, 1876, vol. xviii. p. 431.

Leda jeffreysi, Hidalgo, MolL Marin. Espana, p. 136; and Journ. de Conch., 1877, vol. xxv.

p. 396.
Leda jeffreijm., Jeffreys, Proc. Zool. See. Lond., 1879, p. 579, pi. xlvi. fig. 2.
Leda Jeffreys!, DaU, Bull. Mus. Comp. Zool., vol. ix., No. 2, p. 124.

Hahitat.—iitaiioTL 78, oS" the Azores, in 1000 fathoms ; and Station 344, off" Ascension
Island, in 420 fathoms.

The specimens from the latter locality are more pointed anteriorly than those from
Station 78, approaching in outline Leda lenticula, MoUer, a nearly related species.

Leda hebes, n. sp. (PL XIX. figs. 7-7a).

Testa ovata, postice acuminata, antice acute rotundata, mediocriter convexa, inferuc
late curvata, nitida, alba, concentrice tenuiter striata. Margo dorsi anticus declivis, jDaulo
couvexus, posticus longior, subrectus, sequaliter obliquus. Lunula inconspicua, angusta,
marginata; area j^ostica latior, utrinque carinata, carina altera graciliori utrinque medium
instructa. Linea cardinis modice valida, dentibus circiter decem anterioribus, tredecimque
posticis instructa.

REPORT ON THE LAMELLIBRANCHIATA. 235

This species is transversely ovate, sharply rounded in front, produced and acuminate
liehind. It is considerably inequilateral, moderately convex, transparent white, glossy
near the umbones, finely concentrically striated beneath. The dorsal margins are al)Out
equally oblique, the anterior being the least convex, the posterior longer and almost
rectilinear, or the least concave after a slight rise near the umbones. The beaks are small,
but little raised and glassy. The hinge-plate is fairly strong, and armed with about ten
teeth in front of the centre, and thirteen behind. The lunule is not easUy seen, but is
very narrow and margined by a slender ridge. The postei'ior area is much larger, well-
defined by a ridge radiating from the umbones to the extremity, and has an inner keel
on each side nearer the centre enclosing a space only a trifle larger than the lunule.

Length 4 mm., height 2^, diameter 1^.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

Leda despecta, n. sp. (PL XIX. figs. 8-8a).

Testa parva, rotunde subovata, intequilateralis, convexa, albida, cencentrice fortiter
striata, striis pone medium evanidis. Margo dorsi anticus brevis, leviter declivis,
eurvatus, posticus longior, parum obliquus, subrectus. Latus anticum acute rotundatum,
posticum latins. Umbones rotundati, obtusi, antemediani. Linea cardinis subvalida,
dentibus ad sedecim instructa.

This little species is peculiar on account of its rounded Pisidium-Yike form, and the
rather strong, concentric strife, which become obsolete a little behind the centre of the
valves, and very feeble close to the anterior side. It is a little longer than high, rather
convex, white, glossy, somewhat inequilateral, narrower and more sharply rounded in
front than behind, and prominently curved beneath. The front dorsal margin is short,
slightly curving and oblique, the posterior being longer, straighter, and also a little
sloping. The beaks are rounded and rather lilunt, and decidedly in front of the centre.
The hinge-plate is rather broad, and the teeth, of which about nuie are behind and seven
in front of the beaks, are strongish.

Length 2^ mm., height If, diameter 1.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

This species probably attains a larger size than that of the shells here described.

Leda lata (Hinds)..

Niiciila lata, Hinds, Proc. Zool. Soc. Lond., 1843, p. 99.

Nuada lata, Hinds, Zool. Voy. "Sulphur," p. 64, pi. xviii. fig. 10.

LMa lata, Hanley, in Sowerby's Thes. Conch., vol. iii p. 116, pi. ccxxvii. figs. 44, 4-5

Lceda lata, Sowerby, Conch. Icon., vol. xviii. pi. vii. figs. 44, a, h.

Habitat. — Station 189, Arafura Sea, in 25 fathoms; green mud.

236 THE VOYAGE OF H.M.S. CHALLENGER.

The young shells obtained by the Challenger are not so pointed l^ehind as adult
specimens, and the area between the posterior radiating keels is much smoother and
the carinae themselves are not notched. The concentric strise in this species are coarser
near the umbones, on the hinder side of which, in a slight depression, they are somewhat
flexuose.

Leda inopinata, n. sp. (PI. XIX. figs. 9— 9a).

Testa parva, ovata, convexiuscula, postice brevissime rostrata, fere sequilateralis,
radiatim tenuiter lii-ata, lineis incrementi sculpta, albida ; margo dorsi utrinque leAdter
arcuata, parum declivis ; margo inferior late curvatus, prope extremitatem posticam
sinuatus. Cardo validus, dentibus denis utrinque munitus.

This little species is ovate, rounded in front, and shortly beaked behind. It is
whitish, equilateral, moderately convex, and sculptured with numerous, slender, radiat-
ing lirse, some of which bifurcate towards the lower margin. They do not extend to
the beaked end of the valves, but are there replaced by a number of fine, irregular
wrinkles. The whole surface exhibits fine lines of growth, some of them being particu-
lai'ly well marked. From the umbones a distinct ridge extends to the extremity of the
short rostrum, in front of which the valves are depressed, so that the broadly curved
ventral outline is shaUowly sinuated at this point. The dorsal margin is only slightly
convex on each side, and very gently sloping, and the umbones are smooth at the tip,
small, central, and not much produced. The hinge is rather strong, and bears on each
side ten long, acute teeth. The cartilage -pit is broad and triangular.

Length 3f mm., height 2\, diameter 2.

Habitat. — Station 164, ofi" Sydney, Australia, in 950 fathoms ; green mud.

This is unlike any species of the genus with which I am acquainted, and remai'kable
for the radiating lirae which cover the surface

Leda micans, Adams.

Leda micarw {Ada,ms MSS.), Hanley, in Sowerby's Thes. Conch., vol iii. p. 130, pi. ccxxix. fig. 100.
Lceda micans, Sowerby, Conch. Icon., vol. xviii. pi. vi. fig. 39.

Habitat — Ofi" Le%'Tika, Fiji Islands in 12 fathoms.

New Zealand is the only locality hitherto assigned to this species, and that has not
since been confirmed by Hutton {vide Manual New Zeal. Moll., p. 165).

REPORT ON THE LAMELLIBRANCHIATA. 237

Leda crassa (Hinds).

Nucula crassa, Hinds, Proc. Zool. Soc. Lond., 1843, p. 99.

Leda crassa, Hanley, in Sowerby's Thes. Conch., vol. iii. p. 120, pi. ccxxviii. fig. G9.

Leda crassa, Angas, Proc. Zool. Soc. Lend., 1877, p. 193. ,

Lteda crassa, Sowerby, Conch. Icon., vol. xviii. pi. v. fig. 27.

Habitat. — Station 161, oft' the entrance to Port Philip, South Australia, in 38
fathoms (Challenger) ; Australia (Hinds) ; Port Jackson Heads, in 25 fathoms (Angas) ;
Van Diemen's Land (Mus. Cuming).

A single valve only, half the length of that figured by Hanley, is all that was
dredged oft' Port PhilijD. It undoubtedly belongs to the same species as the type and
two specimens from Sydney presented to the British Museum by Mr. Angas.

Leda messanensis, Seguenza.

Leda acuminata, Jeffreys, Ann. and Mag. Nat. Hist., 1870, vol. vi. p. 69.

Leda acuminata, Seguenza, Atti R. Accad. dei Lincei. Mem., 1877, vol. L p. 1175, pi. iii.

figs. 15-15e.
Leda messanensis (Seguenza, MSS.), Jeffreys, Proc. Zool. Zoc. Lond., 1879, p. 576.

Habitat. — Station 75, off Fayal, Azores, in 450 fathoms ; and Station YHL, off
Gomera, Canaries, in 620 fathoms.

The largest specimen from Station 75 is 7 mm. in length, showing that the species
attains a considerably larger size than the dimensions given by either Jeffreys or
Seguenza.

? Leda rectidoy.'iata, Seguenza.

Leda (Jtmonia) rectidorsata, Seguenza, Atti R. Accad. dei Lincei Mem., 1877, vol. i. p. 1176,
pi. iv. figs. 19-1 9 A

Habitat. — Station II., Setubal, in 470 fathoms.

A single valve from this locality agrees so closely with fig. 19?> in Seguenza's work,
that I cannot find any grounds for separating it.

Leda novce-guineensis, n. sp. (PI. XIX. figs. lO-lOo).

Testa elongato-ovata, postice acuminata, unicarinata, carina aream dorsalem circum-
dante, antice anguste rotundata, sequilateralis, alba, modice convexa, concentrice striata,
striis paulo post medium fere evanidis, antice prope extremitatem acutam paulo flexuosis.

238 THE VOYAGE OF H.M.S. CHALLENGER.

Lunula augustissima, elongata, vix impi-essa, angulo levi circumscripta, prope medium
promiueus. Area latior, profundior, striata, in medio linea impressa arcuata notata.
•Dentes ad 34, acuti, erecti.

This species is of an elongate-oval form, but produced to an acute point behind. It
is about equal-sided, not particularly convex, white and glossy. The valves are of
moderately strong texture, exhibit a slightly curved keel behind, defining the dorsal
area, and are sculptured with fine concentric striae, which are rather deeper towards the
carina than on the anterior side, and are more or less interrupted for a small space a
little in front of the middle, the surface, in consequence, at this part being conspicuously
smooth and glossy. The striae just in front of the keel ascend somewhat suddenly, and
appeal- a little irregular owing to a very faint depression at this point. The dorsal
margins are about equally sloping, the front one being a little convex, the posterior
a trifle excavated at first, then prominent, and again concave at the end. The lunule
is very narrow, defined by a slight ridge, striated and slightly impressed. The area is
much broader, strongly striated, deep at the surrounding keels, prominent along the
middle, and exhibits on each side of it a second fainter ridge, enclosing a space about
the size of the lunule. The teeth are sharp, erect, and about thirty to thirty -four in
number, of which a small majority are in front of the small triangular ligament-pit.

Length 7 mm., height 4, diameter 3.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

This species is a more finely sculptured shell than Leda ventricosa, Hinds, not so
acuminate behind, and is jjeculiar on account of the cessation of the striae near the
middle of the valves.

Leda watsoni, n. sp. (PI. XIX. figs. 11— 11«).

Testa jiarva, alba, subfecjuilateralis, ovata, antice acute rotundata, jjostice acuminata
et bicarinata, inter carinas concava, concentrice lirata, liris tenuibus, fere aequalibus,
interstitiis gracdioribus, ad impressionem flexuosis. Margo dorsi anticus paulo declivis',
leviterque excurvatus, posticus longior, fere rectilinearis, aeque obliquus ; margo inferior
late arcuatus, pone carinam anticam aliquanto emarginatus. Lunula augustissima,
linearis ; area postica latior, lanceolata, impressa, in medio promineus, prope medium
linea elevata paulo arcuata utrinque instructa. Dentes ad 24, mediocriter validi.

This species is of an elongate, trigonally ovate form, sharply rounded in front, and
terminating behind in an acute point. It is white, glossy, moderately convex, and
almost equilateral, the posterior side being only very slightly longer than the anterior.
The valves exhibit two distinct and slightly arcuate keels at the hinder end, one
running from the beaks to the acute extremity, and the other a little below it, the
space between being conspicuously concave. The sculpture consists of fine, regulai-,

KEPOET ON THE LAMELLIBRANCHIATA. 239

concentric lirse, whicli appear rather sharper lietween the carinse than upon the rest of
the surface. The dorsal margins are not very sloping, the front one being slightly
arcuate, the posterior nearly rectilinear, and the lower outline is regularly widely curved,
but faintly sinuated between the keels. The lunule is indistinct, and consists of a very
narrow, linear space, bordered on each side by a very small slender lira. The posterior
area, on the contrary, is large, limited by the upper of the lateral keels, near which it
is concave, and striated by the very fine termination of the concentric lirse. It is raised,
along the central line, on each side of which it exhibits a very slender, elevated, arcuate
raised line. The interior is glossy, and the outer margin is marked with a veiy small
indistinct denticle, indicating the termination of the lower carina. The teeth are fairly
strong and about twelve on each side.

Length 5 mm. height 3, diameter 2.

Habitat. — Station 185, east of Cape York, North Australia, in 135 fathoms; coral
sand.

This species must not be confounded with the young of Leda chuva, from which it
differs in the straighter posterior dorsal margin, finer sculpture, more raised lower keel,
and different dorsal area.

«
Leda ensicxda, Angas.

Leda ensicula, Angas, Proc. Zool. Soc. Lond., 1877, p. 177, pi. xxvi. fig. 27.
Habitat. — Station 161, off the entrance to Port Philip, South Australia, in 33 fathoms;
sand.

The type of this remarkable species, presented to the British Museum ])y Mr.
Angas, was dredged off Port Jackson Heads, in 45 fathoms, by Mr. Jolm Brazier of
Sydney. Its form is so peculiar, and the description given by Angas so good, that there
is little fear of its being confounded with any other species. I may mention that the
teeth, which are not referred to by Angas, are elongate, very acute, and numerous,
especially on the rostrate side.

Leda corhuloides, n. sp. (PI. XX. figs. 1-la).

Testa triangulariter ovata, crassiuscula, pallide flavescens, gequilateralis, antice
breviter arcuata, postice acuta, impressionem radiantem hand profundam prope
extremitatem exhibens, transversim fortiter lirata, antice liris 2—3 obsoletis radiantibus
inter costas ornata. Margo dorsi anticus rectiusculus, obliquus, posticus leviter con-
cavus, seque declivis; margo ventris late curvatus, postice ad impressionem breviter
sinuatus. Lunula elongata, auguste elliptica, impressa, radiatim tenuiter lirata ; area
valde latior, acute ovalis, similiter lirata, porca rotundata circumdata. Linea cardinalis
valida, dentibus quindenis utrinque instructa.

240 THE VOYAGE OF H.M.S. CHALLENGER.

This is a solid, dirty whitish, little species, equUateral, fairly convex, of a
triangularly ovate form, rather sharply rounded in front, and acutely, but shortly,
rostrate behind. The valves exhibit a shallow radiating depression down the posterior
side, which is defined in front by a faint ridge, and causes a feeble emargination in
the otherwise regularly and broadly curved lower margin. The sculpture consists of
numerous strong concentric riblets, wdiich are furthest apart towards the beaks, and
gradually approximate as the shell increases. They become slender by degrees at the
sides, and in a great measure terminate at the rounded ridges which border the lunule
and area. In addition to the costse there ai-e two or three faint radiating irregular
lii'se between the libs which run from the umbones to the anterior end of the ventral
outline. The lunule is long, narrowly elliptical, and somewhat sunken, whilst the area
is much broader and sharply oval, both being ornamented with, fine radiating lirse, the
continuations of some of the concentric riblets. The dorsal margins are about equally
oblique, the anterior being nearly rectilinear, and the posterior a little concave. The
hinge-plate is rather strong, and furnished with about fifteen teeth on each side the
minute central cartilage -pit. Interior glossy, thickened.

Length 6^ mm., height 5J, diameter 3i.

Habitat. — Station 188, south of New Guinea, in 28 fathoms; green mud.

In general appearance this species closely resembles Leda ventricosa of Hinds, but
may be distinguished from it by its smaller size, comparatively greater solidity, the
more distant riblets upon the umbones, the more distinct impressed ray, and the
absence of the puckers or nodules on the lunule.

Leda neceriformis, n. sp. (PI. XX. figs. 2— 2a).

Testa parva, elongata, postice anguste rostrata et biearinata, parum convexa, valde
insequUateralis, concentrice tenuiter striata. Margo dorsi anticus brevis, valde curvatim
declivis, posticus elongatus, minus obliquus, concavus. Margo ventris antiee et in
medio late arcuatus sub rostrum leviter incurvatus. Dentes ad triginta, insigniter cavi.
Pagina interna nitida, per medium rostri porcata.

This species is elongate, slenderly beaked behind, rather compressed, very
inequilateral, white and sculptured with fine concentric strise. From the beaks two
keels run to the rather squarely truncate end of the rostrum, the space between them
and between the upper one and the dorsal margin being concave. The front dorsal
slope is short, very much curved and very oblique, the posterior, on the contrary, being-
long, concave, and less sloping. The anterior end is sharply rounded, the lower outline
broadly arcuate in front and along the middle, but feebly incurved at the rostrate
extremity. The umbones are small, and situated at about two-fifths of the total length

EEPORT ON THE LAMELLIBRANCHIATA. 241

from the anterior end. The hinge-teeth are al)out thirty in number and remarkabl}'
excavated on the outside, those on the longer side being rather more numerous than
those on the anterior margin, only extending along a trifle more than half its lengtli.
The interior of the valves is glossy, and along the middle of the rostrum exhibits a.
slight curved ridge.

Length 5j mm., height 2|, diameter 1-|.

Habitat. — Station 185, east of Cape York, North Australia, in 135 fathoms; coral
sand.

Externally this curious little shell recalls to mind certain little rostrate forms of tlio
genus Necera.

Leda ramsayi, n. sp. (PI. XX. figs. 3— 3a).

Testa elongata, antice acute rotundata, postice producta, anguste rostrata, compressa,
valde insequilateralis, bicarinata, carinis ab umbonibus ad extremitatem posticam decur-
rentibus, concentrice suljfortiter lirata, liris supra carinam inferiorem subito angulatis.
Margo dorsi antieus leviter convexus, valde declivis, posticus fere duplo longior, incur-
vatus, minus oblicpius. Ventris margo late arcuatus, postice hand profuude sinuatus.
Area postica dorsalis lanceolata, concava, incrementi lineis tenuissimis striata, carina
superiori filiformi marginata. Umbones Iseves, nitidi, longe ante medium collocati.
Dentes numerosi, conferti, angulares. Pagina interna nitida, ad extremitatem rostri
porca mediani brevi instructa.

This species is rather longly rostrate behind and sharply rounded in front. It is
very inequilateral, the acute smooth umbones being situated at about one-third of the
entii-e length of the shell from the anterior end. The front dorsal slope is short, veiy
oblique, and somewhat excurved, the posterior, on the contrary, being very long, less
sloping, and gently concave. The lower outline forms a broad curve with a very faint
sinuatiou near the hinder shortly truncate end. The valves have two radiating ridges,
whereof the upper is slender, keel-like, and extends from the apex to the uj)per corner
of the rostrate extremity, the lower being rounded, broader, and descending to the
inferior angle. The sculpture consists of rather strong concentric lirse, which are
suddenly turned at right angles upon the slightly concave space between the radiating
keels, and, owing to the produced character of that side of the valves, are further apart
than on the other portion of the surface. The hinder dorsal area is concave, almost
smooth, and sharply defined by the uppermost carina. The teeth are numerous, close-
set, and angular, those on the posterior side extending along two-thirds of its length.
Along the middle of the rostrate end internally is a short curved ridge.

Length 7 mm., height 4, diameter 2 .

Habitat. — Station 164, off Sydney, New South Wales, in 950 fathoms; greerf mud.

(ZOOL. CHALL. EXP. PART XXXV. — 1885.) Jim 31

242 THE VOYAGE OF H.M.S. CHALLENGER.

Yoldia, Moller.

Yoldia lischkei, u. sp. (PI. XX. figs. 4-4?>).

Testa niedioeriter couvexa, tenuis, paulo iusBquilateralis, oblonga, utriuque hians,
autice acute rotundata, postice sursum subrostrata et radiatim baud profuude impressa,
iiicremeuti liueis teuuibus, bic illic paucis fortioribus, sculpta, epidermide flaveseeuti-
olivacea, colore saturatiori sparsim zonata, amicta. Margo dorsi anticus declivis, leviter
arcuatus, posticus longior, fere borizontalis, paulo concavus. Margo ventris late
arcuatus, integer. Lunula elongata, angusta, impressa, in medio prominens. Area
postica latior, in medio producta, margine acuto cii-cumdata. Umbones parum elevati,
])aulo antemediani, postice inclinati. Linea cardinalis mediocriter fortis, dentibus
uumerosis erectis instructa. Fossa ligamenti lata, baud profunda, inferne arcuatim
marginata. Pagina interna alba, concentrice plus minusve pellucido-cseruleo zonata.
Sinus pallii profundus, latus, rotundatus, paulo ante medium extendens.

Length 29 mm., height 17, diameter 11.

Habitat. — Station 232, off luosima, Japan, in 345 fathoms ; green mud.

This species very closely resembles Yoldia japonica of Adams and Reeve, but is,
1 think, distinct.

That species is a smoother shell, of a paler colour, more convex, more inequilateral,
the posterior side being longer in proportion to the anterior ; also it is not so high, and
consequently has a longer and more cylindrical appearance. The present species has a
faint radiating depression down the hinder side, which does not exist in Yoldia
japonica, the posterior dorsal area is more prominent along the middle, and the
ligament-pit is broader, not so deep, and less projecting inwards. From a conchological
point of view, the genera Leda and Yoldia appear to pass gradually into one another,
the extent of the gape at one or both ends, the depth of the pallial sinus, &c., varying
to any extent in a large number of species.

Yoldia isonota, Martens (PI. XX. figs. 5— 5&).

Yoldia isonota, Martens, Sitzungsb. Gesellscli. naturf. Freimde, Berlin, 1881, p. 79.

Testa transversa, convexa, sequilateralis, antice acute rotundata, postice superne
subnasuta, in medio sinuata, impressione radiante notata, incrementi lineis costiformibus
in impressione posteriori flexuosis sculpta, epidermide crassiuscula, flavo-olivacea, supra
costellis saturatissima, induta. Margo dorsi utrinque vix declivis, postice rectus, antice
levissime excurvatus. Margo ventralis late arcuatus. Lunula nulla. Area postica
aliquanto indistincta, leviter impressa, elongata, angusta. Linea cardinis mediocriter
valida, dentibus ad septendecim acutis utrinque munita. Fossa ligamentalis profunda,
paulo intus projecta. Pagina interna nitida, iridescens, albido cjeruleoque zonata, plus
minusve flavo tincta.

REPORT ON THE LAMELLIBRANCIIIATA. 243

This species is considerably swollen, almost exactly equilateral, scarcely gaping at
either end, elongate, nearly twice as long as high, sharply rounded at the anterior end,
broader behind and shortly rostrate above, with a distinct but not veiy deep sinus just
l^eneath, which marks the termination of a slight depression extending from the uml^ones.
It is ornamented at intervals with very strong raised ridges, marking periods of growth,
so that the surface might be described as ridged and sulcated. The epidermis is thickish,
of a dark olive tint upon the lirse, paler and yellower between them. The dorsal margin
is only very little sloping on both sides, quite rectilinear behind, and very slightly
excurved in front. The umbones are small, central, and but very little raised above
the dorsal line. The hinge-plate is not remarkably strong, and in the largest specimen
bears seventeen sharp close-set teeth on each side the ligament-pit, which is deep and a
little prominent within the valves. The interior is glossy, somewhat iridescent, whitish,
zoned with a bluish tint, and stained at times with a pale reddish or yellowish colour.
The pallial sinus is short, narrow, and rather acute.

Length 24 mm., height 13, diameter 12.

Habitat. — Balfour Bay, in 20 to 60 fathoms ; Betsy Cove, in 15 to 25 fathoms ;
Howe's Foreland, in 95 fathoms; and Station 149g, in 110 fathoms; all oft" Kerguelen
Island.

This species cannot be conveniently compared with any at present known. Tlic
specimens described by Professor Martens were rather smaller than the largest ohrained
by the Challenger.

Yoldia suhcequilateralis, Smith.

Toldia sitbcpqmlaterah's, Smith,
Yoldia suhxquilaferalis, Smith,

Habitat. — Station 149d, Eoyal Sound, Kerguelen Island, in 28 fathoms ; volcanic

Toldia sitbcpquilateralis, Smith, Ann. and Mag. Nat. Hist., 1875, vol. xvi. p. 73.
Yoldia suhcequilateralis, Smith, Phil. Trans. Roy. Soc, 1879, vol. clxviii. p. 187.

mud.

Besides the internal cartilage, the valves are connected above by a slight external
ligament or thickening of the epidermis on each side of the umbones, which are generall}-
eroded. The species is characterised by its compressed form, its gaping ends, and few
teeth. The interior is bluish-white, zoned with a darker tint.

Sarepta, A. Adams.

Sarepta ahyssicola, n. sp. (PI. XX. figs. 6—66).

Testa tenuis, parva, insequilateralis, antice angusta, acute rotunda ta, postice latior,
nitens, alba, aliquanto iridescens, incrementi Lineis tenuissimis sculpta. Margo dorsi
anticus brevis, paulo excurvatus et declivis, posticus parum arcuatus, minus obliquus.
Ventris margo late curvatus, antice oblique ascendens, postice subito sui'sum arcuatus.

244 THE VOYAGE OF H.M.S. CHALLENGER.

paulo post medium maxime prominens. Umbones haucl acuti, ^jarum produc-ti, aute-
mediaiii. Linea cardinis gracilis, debilis, dentibus 8—9 utrinque instructa. Ligamentum
fuscesceus, brevis, partim externum, j^artim margiuale.

This small species is very tliiu, rather convex, considerably inequilateral, of an
irregular ovate form, narrower in front than behind, white, very glossy, a little
iridescent, and sculptured with excessively fine lines of growth. The front dorsal slope
is short, the least convex, and a little oblique, the posterior being longer, also faintly
arcuate, but rather less sloping. The ventral outline is gently rounded, slowly up-
curving in front, and together with the dorsal margin forms a sharply i-ounded extremity.
The lower margin is most prominent a trifle behind the middle of the valves, and rises
posteriorly more suddenly than in front. The umbones are bluntly rounded, only
slightly elevated, and situated at about a third of the total length from the anterior
end. The hinge-plate is slender, and furnished with about eight or nine l)lunt-topped
teeth on each side, a small space under the beaks being edentulous. The ligament is
small, brown, partly internal in a small pit lieneath the umbones, and partly visible
externally, being located in a groove on the margin of the valves behind the beaks.
The interior is smooth, and the muscular scars are not clearly discernible.

Length 4^ mm., height 3^, diameter 2^.

Habitat. — Station 246, Mid North Pacific Ocean, in 2050 fathoms ; and Station
281, Mid South Pacific, in 2385 fathoms.

The specimen from the latter locality apparently belongs to this species, differing
Ijut very slightly in lieing the least more strongly concentrically striated. In the
typical form of this genus, Sarepta speciosa, A. Adams, I also find a slight marginal
ligament besides the more distinct internal cartilage.

Malletia, Desmoulins.
Malletia gigantea, Smith.

Solenella yiganfea, Smith, Ann. and Mag. Nat. Hist., 1875 (July), ii. 72.

Solenella ffigantea, Smith, Phil. Trans. Ro}'. Soc, 1879, vol. clxviii p. 187, pL ix. fig. 19.

Habitat. — Betsy Cove, Kerguelen Island, in shallow water ; also at Balfour Bay, in
20 to 60 fathoms.

A fine species, easily recognised by its large size, its form, and the few closely ranged
radiating strije upon the anterior side.

Malletia arrouana, n. sp. (PI. XX. figs. 7-7b).

Testa oblonga, subcpiadrata, valde intequilateralis, tenuis, convexa, antice oblic[ue-
curvata, postice arcuatim truncata, radiatim obsolete bisulcata, epidermide tenui dilute

REPORT ON THE LAMELLIBRANCHIATA. '245

oliviicea induta. Superficies nitida, incrementi lineis, in medioque aliis paulo obliquis
sculpta. Margo dorsi antieus brevis, leviter deelivis, rectiusoulus, posticus vix oliliquus,
levissinie incurvatus. JMargo ventralis late arcuatus antice curvatim ascendeus.
Umbones paulo prominentes, latus anterius versus inclinati, in ^ longitudiuis collocati.
Lunula augustissima, impressa; area postica angusta, utrinque bicarinata. Linea cardinis
gracilis, dentibus numerosis instructa. Pagina interna, nitens, cseruleo-albida, lineam
pallii mediocriter profuude sinuatam exliiljens. Ligamentum olivaceo-fuscum, promineus.

This interesting species is rather thin, convex, markedly inequilateral, of an ol)long,
squarish form, especially at the posterior side, which is ol)liquely and slightly arcuately
truncate. Down the posterior side two faint depressions radiate from the umbones, the
one to the lower rounded extremity, the other to the middle of the truncated side. The
epidermis is glossy, thin, of a pale olive tint, and exhibits rather strong lines of growth,
especially in front, and on the central portion of the valves other elevated thread-like
lines crossing them obliquely. These slanting lines are not present in the early stages
oi growth. The front dorsal margin is short, nearly rectilinear, and just a little oblique,
the posterior being much longer, nearly horizontal, and verj^ slightly incurved. The
lower outline is very gently arcuate, and rises more gently in front than behind. There
is a very narrow lunule, which is sunken and well defined. The posterior dorsal area
is also narrow, excavated, bounded by a raised slender ridge, and has a slender thread-
like keel on each side, mid-way between the central divisional line and the outer ridges.
The umbones are a little raised above the dorsal line, incline towards the front, a trifle
incurved, and located at about one-third of the entire length of the shell from the
anterior end. The hinge-plate is rather slender, and Itears (in the largest specimen
under examination) about fifty-five not very long teeth, of which about fourteen are in
front of the umbones. The ligament is prominent and of a browTiish-olive tint. The
interior is glossy, bluish-white, and on account of the thinness of the shell exhibits more
or less of concentric sulcation, corresponding to the external ornamentation. The
pallial sinus is moderately deep, not reaching to the centre, and sharply rounded at the
end.

Length 204 mm., height 12^, diameter 8.

Habitat. — Station 191, near the Arrou Islands, in 800 fathoms; green mud.

Malletia ohtiisa, G. 0. Sars.

Malletia obtusa,G. 0. Sars, Moll. Eeg. Arct. Norv., p. 41, pi. xix. figs. 3, a, b.
MulJftia ohtusa, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 586.
Yoldla ohtusa, Sars, Remark. Forms Auimal Life, p. 23, pi. iii. figs. lG-20.
Yoldia abyssicola, Sars, Porhandl. Vidensk. Selsk. Cliristiania, 1858, p. 86.

Habitat. — Station 47, south of Nova Scotia, in 1340 fathoms; and Station 45, off
the east coast of the United States, in 1240 fathoms.

246 THE VOYAGE OF H.M.S. CHALLENGER.

Several Stations iu the Atlantic have already been recorded by the late Dr. Gwyu
Jeffreys for this species.

Malletia pallida, u. sp. (PI. XX. figs. 8-8a).

Testa convexiuscula, insequilateralis, augusta, elongata, anticc acute rotundata,
postice angustior, subacuminata, uitida, albido-flavescens, incrementi lineis tenuibus
striata, lineis paucis albidis radiantibus ornata. INIargo dorsi anticus leviter declivi.=s,
parum arcuatus, posticus longior, rectilinearis, vix obliquus. Margo inferior late
curvatus, postice indistincte sinuatus. Umbones parum prominentes, haud acuti,
involuti. Ligamentum elongatum, gracile, vix prominens, pone umbones carina
gracillima utriuque marginatum. Linca cardinis angusta, dentilnis ad 36 instructa.
Pagina interna alba.

This species is thin, inequilateral, moderately convex, very glossy, white, and
clothed wdth a very thin pale yellow epidermis. It is long, sharply rounded at the
anterior end, narrowed and bluntly acuminate behind. The sculpture consists of very
fine lines of growth and a few coarser striae near the lower margin at the central part
of the valves, and at the posterior end there are two faint radiating white lines and a
few others still less noticeable upon the rest of the surface. The front dorsal margin is
a little convex and oblique, the posterior being considerably longer, rectilinear, and
about equally inclined. The ventral outline is regularly broadly curved, and exhibits
only the faintest indication of a posterior emargination. The umbones are small,
incurved at the tips, a little raised above the dorsal line, and situated at about three-
eighths of the total length from the anterior end. The ligament is small, narrow, and
bordered on each side by the raised keel-like posterior edge of the valves. In front of
the beaks there is also a slight ligament or thickening of the epidermis which connects
the valves. The hinge-plate is moderately slender, and furnished with about thirty-six
denticles, of which about twelve are anterior to the centre. The interior is white, and
exhibits only a shallow sinus in the pallial impression.

Length 16^ mm., height 9^, diameter 6.

Habitat. — Station 137, Mid South Atlantic, between Tristan da Cunha and the
Cape of Good Hope, in 2550 fathoms ; red clay.

Malletia veneriformis, n. sp. (PI. XX. figs. 9— 9a).

Testa ovata, convexa, paulo insequilateralis, alba, nitida, concentrice tenuiter lirata
et sulcata. Umbones prominentes, iucurvati, antice versi. Dentes numerosi, utriuque
elongati, acuti, in medio umbones infra minuti, haud interrupts Ligamentum
marginale, angustum, in suico supra dentes parvos, infra umbones situm.

REPORT ON THE LAMELLIBRANCIIIATA. 247

This species is sliaped nut uulike certain forms of Cytherea.- It is rather inequi-
lateral, ovate, somewhat convex, semitransparent white, and sculptured with regular fine
concentric lira? and intervening slender sulci. The front dorsal margin is almost
straight, and considerably oblicjue, the posterior being almost equally sloping, longer,
and a triHe more curved. The lower outline is gently arcuate and about equally
ascending at both ends, which are sharply rounded. The umbones are prominent,
incurved, smooth, glassy, and anteriorly inclined. The hinge-teeth, about thirty in
number, form one unbroken series from side to side, those in the centre under the
umbones being minute, whilst those at the sides are very long, erect, and acute. Owing
to the semitransparent texture of the shell, the pits for the reception of the correspond-
ing teeth in the two valves are distinctly seen on both the front and hinder dorsal
areas. The ligament is small, and placed in a narrow groove between the small teeth
just behind the' tip of the beaks and the dorsal edge, and is probably only very little,
if at all visible externally. The interior of the valves is smooth and highly glossy.

Length 8 mm., height 6^, diameter 4.

Habitat. — Station 33, off Bermuda, in 435 fathoms ; also Station 24, off Culebra
Island, West Indies, in 390 fathoms.

On account of the glossy surface, the pallial line of this species is very indistinct.
It is very unlike the t5rpical forms of Malletia in texture, form, and sculpture, and it-
is questionable whether, in the living state (all the specimens under examination being
dead, separated valves), it is furnished with a similar kind of epidermis. As, however,
the hinge-characters are the same, it seems to me advisable at present to locate it in
this genus.

Malletia cuneata, n. sp. (PI. XX. figs. 10— 10a).

Testa parva, modice convexa, subovata, antice acute rotundata, postice angustata,
acuminata, alba, conceutrice teuuiter striata, striis latus posterius versus paulo evanidis.
Margo dorsi anticus brevis, arcuatim descendens, posticus longior, declivis, minime
excurvatus. Margo ventralis late rotundatus, postice perindistincte sinuatus. Umbones
prominentes, antemediani, involuti, hand acuti, antice inclinati. Linea cardinis medio-
criter valida, serie continua dentium ad triginta instructa, paucis prope umbones
minimis.

This smaU species is considerably inequilateral, broader in front than behind, where
it is somewhat acuminately produced, rather convex, white, and sculptured with fine
concentric striae, which become less apparent towards the hinder extremity. The dorsal
margin is somewhat oblique on both sides, the anterior portion being gently arcuate,
the posterior almost twice as long and rather straighter. The ventral outline is widely

248 THE VOYAGE OF H.M.S. CHALLENGER.

curved, sometimes, but uot always, with the faiutest trace of a sinus behiud,
indicating a \'ery inconspicuous radiating depression upon the surface of the valves.
The umbones are prominent, smooth, incurved, directed towards the front, and situated
considerably^ in advance of the centre. There is neither lunulc nor posterior area. The
hinge -plate is fairly strong, broader in front than behind, and supports an unbroken
series of about thirty teeth, of which ten are anterior to the beaks. The central
denticles are small, Ijut the laterals are fairly long and acute. The ligament is placed
in a small narrow groove above the teeth, just behind the apices. The scars and
pallial line are indistinct.

Length 5 mm., height 4, diameter 3.

Habitat. — Station 24, ofFCulebra Island, West Indies, in 390 fathoms; Pteropod ooze.

This is a much more slender species than MaUetia veneriformis, much narrower
posteriorly, and more finely sculptured. The hinge-characters of both, however, are
alike.

Family A R c i D .e.

Subfamily PectunculixvE.

Glom us, Jeffreys.
Glomus nitens, Jeffreys.

Glomus nitens, Jeffreys, Ann. and Mag. Nat. Hist., 1876, voL xviii. p. 433.
Glomus nitens, Jefifreys, Proc. Zool. Soo. Lond., 1879, p. 573, pi. xlv. fig. 5.

Habitat. — Station 323, off the Ptio de la Plata, in 1900 fathoms ; blue mud.

This species has been recorded liy the late Dr. Jeffreys from several stations in the
North Atlantic, at depths of from 500 to 1750 fathoms, but this is its first occurrence
so far south.

The cartilage is placed in a narrow groove parallel with the hinder dorsal margin,
AA'hich extends from the umbones a short distance under the teeth on that side.

Glomus jeff're y si, n. sp. (PI. XXI. figs. 1—1 6).

Testa minuta, teuuissima, mediocriter convexa, sequilateralis, subcii'cularis, postice
oblique subtruncata, ibique impressione radiante baud profunda exhibens, albo-peUucida,
nitida, incrementi lineis tenuissimis sculpta. Umbones pai-va, paulo supra margiuem
projecti, baud acuti. Linea cardinis mediocriter valida, dentibus cireiter sedecini
(quorum sex ante medium cseterique postmediani sunt) instructa. Ligamentum
Langustum, in fossa obliqua umbones infra locatum.

REPORT ON THE T.AM KLTJBRANCH [ATA. 249

Leugtli 21 luni., height If^, <li;iiiR'tcr I.

Habitat. — Station 24, off Culebra Ishiiid, West Indies, in 390 fathoms; Pteropod ooze.

This species is very like Gloimis nitcus in some respects, l)iit is well distinguished
by the shallow depression down tlic jiosteiior side, wliidi causes the margin at that fiart
to be somewhat truncate or even faiuth' incurved.

Glomus simplex, n. sp. (PL XXI. figs. •l—lb).

Testa ovato-circularis, fere ajcpiilateralis, tenuis, paulo convexa, albida, sulipellu(;ida,
nitida, inerementi liueis tenuibus striata. Umbones parvi, le^ater supra marginem
produeti. Linea cardiuis angusta, dentibus anticis ad novem posticisque circiter
quindecim instructa.

Length 4|, mm., height '?,\, diameter 2.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms; Pteropod ooze.

This species in texture, sculpture, and the hinge-characters closely resembles GIodi u.'i

nitens, l»ut is distinguisha1>le by its different form, being more ovate or longer in

proportion to its height.

Glomus incBquilatendis, n. sp. (PI. XXI. figs. 3-36).

Testa minuta, olituse ovata, mediocriter convexa, tenuis, insequihiteralis, albida,
inerementi lineis tenuibus sculpta. Mai-go dorsi anticus brevis, declivis, rectiusculus aut
vix arcuatus, posticus longior, minus obliquus, leviter excurvatus. Umbones parvi,
antemediani, paulo prominentes. Linea cardinis mediocriter valida, dentibus anterioribus
octo posticisque ad decern munita. Pagina interna nitida, cicatrice antica rotundata et
postica majori longiori, impressa. Pallii impressio simjjlex, hand sinuata.

Length 2j mm., height if, diameter 1.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms; Pteropod ooze.

This species is c[uite distinct in form from any of the other -species, being decideiU)'
less equilateral. Its teeth also are rather stronger, the ligament less oblique, and the
muscular impre.ssions more distinct. Whether this and the other forms exceed their
known dimensions, it is imjDossible to say, l)ut in all })robability they do to some extent.

Glomus sp.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms; Pteropod ooze.

As only a single minute valve of this species was obtained, which is evidently
distinct from any of those here described, I refrain from naming it at present. It is

(ZOOL. CHALL. EXP. — PART X.KXV. — 1885.) Mm 32

250 THE VOYAGE OF H.M.S. CHALLENGER.

iiiirrower and longer than any of tlif other forms, oval, a little narrower posteriorly than
in front, and somewhat inequilateral, the hinder side being the longer. It is glossy,
sculptured with fine lines of growth, and furnished with about fifteen hinge-teeth
altogether (six anterior and nine posterior), which are peculiar in having their inner side
rise direct from the inner margin of the hinge-plate, and in being less obliquely placed
than usual, and rather far apart.

Pectuneulus, Lamarck.

Pectunculus pectinatus (Gmelin).

Area pecfi /lata, Gmelin, Syst. Nat., p. 3313.

Pectuneulus pedinatus, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 494.

Pectuneulus pectinatus, Ileeve, Conch. Icon., vol. i. pi. vi. fig. 28.

Habitat. —Station 113, off' Fernando Noronha, in 1010 fathoms; hard ground.

The few specimens I have seen of this species all agree in having a small brown
blotcli on the dorsal margin on each side of the umbones, and a much more conspicuous
oblique ray on each side but more remote. This feature is best seen when the umbones
are towards the eye.

Pectuneulus stellatus (Bruguiere).

Area stellata, Brnguiere, Ency. Meth., p. 117.

Pectuneulus stellatus, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 491.

PeetHncnhis stellaius, Reeve, Conch. Icon., vol. i. pi. ii. fig. 5.

Habitat. — Tenerife, in 70 fathoms (Challenger).

The Tenerife .shells are mostly of a purple-reddish tint, zoned at intervals with a
darker colour, and invariably have the white star-shaped patch at the umbones. They
are also rayed with slender white lines, and some of the specimens ai'e ornamented with
wavy concentric reddish lines. The interior of the largest shells is generally totally
white, but some of the smaller specimens have the central portion of the valves stained
and blotted with deep purple -brown.

The epidermis of this species is very deciduous, only the smallest portion at the
circumference of the valves apparently ever remaining. It is not of the hairy character
of Pectuneulus pilosus, Pect^inculus siculus, and some others, but has a more chaffy
appearance. The surface of the valves, besides the concentric lines of growth, has
scarcely any sculpture, the fine radiating striae met with in Pectmiculus siculus and
some others being entirely absent.

REPORT ON THE LAJVIELLI BRAN t;HI ATA. 251

Pectuncuhis formosus, Reeve.

Pedunculus fonnoms, Reeve, Conch. Icon., vol. i. pi. viii. fig. 48i.
Habitat. — St. Vincent, Ca])e Verde Islands, in 7 to 20 fathoms.

The figure 48a of Reeve seems to represent a distinct species. The shells from the
above locality, which I have identified as Pectunculus formosvs, are very little more
than an inch in length. They are of a whitish ground colour, and variegated with a
considerable amount of interrupted purplish-red rays as depicted by Reeve. The
sculpture consists of concentric lines of growth, which at the sides become a little
raised. A thinnish epidermis covers portions of the surface, more especially near the
outer margin. It is finely concentrically lamellated and radiately ciliated, and when
removed the surface exhibits more or less clearly punctured lines which indicate the
position of the cilia. The umbones appear to be invariably white, and the hinge-plate
is blotched within on each side with purple-brown or red. The teeth are arranged in
an uninteiiupted arcuate series, and are about twenty to twenty-four in number. The
interior of the valves is for the most part white, and the outer margin is finely
denticulate.

This species is very closely allied to Pectunculus stellatiis, and, indeed, may
eventually prove to be a variety of it, differing somewhat in the style of its colouring
and the epidermis.

Pectunculus holosericiis, Reeve.

Pectunculus holose/iciis, Reeve, Conch. Icon., vol i. ]il. iv. fig. 18.
Pectunculus holosericus, Reeve, Proc. Zool. Soc. LoncL, 1843, p. 34.
Axinia holosericus, Angas, Proc. ZooL Soc. Lond., 1867, p. 932.

Habitat. — Port Jackson, in 2 to 10 fathoms (Challenger); Broken Bay, New South
Wales (Brit. Mus.) ; Watson's Bay (Angas).

On the soft velvety epidermis being removed, the entire surfoce of this species is
minutely reticulated with radiating and concentric striae. The t;olour is usually light
brownish-white, generally variegated at the beaks with a few pale brownish-red zig-zag
markings. The interior is at times totally white, but frequently more or less stained
towards the pallia! line o)i one side with a rich purple-brown tint.

? Pectunculus strlatularis, n. sp., (Lamarck ?) Reeve.

Pectunculus striatulnris, (Lamarck) Reeve, Conch. Icon., vol. i. pi. vi. fig. 27.

Habitat. — Port Jackson, New South Wales, in 6 to 7 fnthoms : and Station 212.
south of the Philippine Islands, iu 10 fathoms.

252 THE VOYAGE OF H.M.S. CHALLENGER.

The identification of this species either from the description given by Lamarck or
that in Reeve's work would be quite impossible ; but, having the specimen delineated in
the Conchologia Iconica for comparison, I am able to state that the few valves from the
above localities probably belong to it. They are, however, paler in colour, lack the
brown stain on the anterior side within the valves, and the denticles within the outer
margin are rather more grooved. Reeve's sliell is said to have come from the west
coast at Swan River.

Pectunculus heddomei, n. sp. (PL XVIII. figs. 1—1/;).

Testa subcompressa, rotundata, crassa, antice peculiariter radiatim constricta, alba
vel dilute fuscescens, hie illic fusco maculata, radiatim costata, costis circa 24 parum
elevatis, rotundatis, quam sulcis intermedianis valde latioriljus, incrementi lineis confer-
tissimis elevatis, undulatis insculpta. Pagina interna alba, utrinque supra cicatrices
fusco radiata, sa^pe marginem versus fusco tincta. Margo internus plerumque alba,
dentibus circiter 17 latis concavis munitus.

This species is about as long as high, rather fiat, roundish, and solid. It is of a
white or light brown colour, spotted and stained with dark rich lirown upon the radiat-
ing ribs. These are very broad, flattened, rounded at the top, and much wider than
the grooves separating them, indeed, they almost, join one another at their leases. They
are about twenty -four in number, those on each side being consideraljly more slender
than those down the middle. The remaining sculpture consists of closely packed wavy
conspicuous sublamellated lines of growth which pass over and between the costse. At
the anterior end there is a faint depression which radiates down the valves, marking oft',
as it were, a large prominent lunule. The ligamental area is deep and narrow, slightly
separating the acute beaks. The hinge-plate is moderately broad, white, and furnished
with seven to ten oblique denticles, forming a slightly curved series on each side. The
interior is white at the middle and towards the umbones, but generally more or less
stained with lirown, nearer but not upon the margin. The muscular scars always have
a broad dark lu'own ray upon them, and are bordered within by a raised edge. The
margin of the valves is white, shallowly scalloped at the edge, and armed within with
about seventeen broad flattened concave denticles.

Length 42 mm., height 44, diameter 22.

Length 42 mm., height 41, diameter 21.

Habitat. — Station 162, oft' East Moncoeur Island, Bass Strait, in 38 fathoms; sand
and shells.

This species is remarkable on account of its Ijroad and not much raised ribs, and
the dark brown rays on the muscular impressions. The depression down the anteiior
side is not very conspicuous, but apparently })resent in all specimens.

REPORT ON THE LAMELLIBRANCHIATA. 253

This species must not Ije conlbuiuled with Pectitnmlus laticofitatus, Quoy and
Gaimard, a form common in some parts of New Zealand. That species is Ijroader at
the vipper part, and has many more and finer ribs, lacks the depression down the front
of the valves, has fewer hinge-teeth, more marginal denticles, and im Inown mark on
the hinder muscular scar, besides other minor diti'crciices.

It is possible this may be the Pectunculus ^fiabdlatiis of Tenison-Woods (Trans.
Roy. Soc. Victoria, 1878, vol. xiv. p. Gl), but I cannot (piite reconcile it with the
description. I do not find the number of ribs ever amounting to tiiirty-five, nor do
they "become very close at the sides as the shell grows." If by "alt." Mr.
Tenison-Woods means the diameter of the closed valves, I sliould think he has given
the wTong measurement (44 mm.) under this head, or else his character " tinnidiuscula"
must be incorrect. Pectunculm heddomei is only al)out lialf that extent in diameter,
and decidedly flatter than Pectunculus htticosfatn.';.

No mention is made of the peculiar dark In-owu muscular scars in Pcctumnlus
flcihellahis, which is a prominent feature in the present species, the interior lieing
described as if entirely of an " intense fulvous livdwn."

Pectunculus lutirus, Lamarck.

Pectuncnhts litreiw, Lamarck, Aiiim. sans vert., ed. 2, vol. vi. j). 49.5.
Pectunculus vitreus, Reeve, Condi. Icon., vol. i. pi. viii. Kgs. 45, a, 1j.
Pectunculus vitreus, Ilanley, Cat. Eec. Biv. Shells, p. 165, pi. xix. tig. 2S.

Habitat. — Station 188, soutli of New Guinea, in 28 fatJioms (Challenger) ] Cape
York (Brit. Mus.).

The ribs of this remarkal)ly flattened species are two or three times more numerous
towards the outer margin than near the umbones, which results from their being
dichotomous when the shell is young, and other intervening ones being produced during
growth.

When in fresh (jondit:ion the radiating slender costie are flnely nodose, and the
sulci between them are very distinctly concentrically striated. The interior of the
valves is either entirely white or more or less stained with l)rii\vn. and is also A*eiy finely
radiately ridged.

The hinge is very peculiar, consisting of two all but straight series of teeth, which
convero-e to an angle of about 105°. The teeth arc about fourteen on cai-li side, mostly
o-rooved at the top, and placed almost parallel with the dorsal margin. The .sculpture
and hinge of Pectunculus norce-guineensis, Angas, is precisely of the same character as
in this species, and I am of opinion that when our series of specimens is sutticiently
large, it will be found to be onl}- a variety, dift'ering from the XjV^ merel}- in outline.

254 THE VOYAGE OF H.M.S. CHALLENGEU.

LinfKypsis, Sassi.

Limopsis marionensis, u. sp. (PL XVIII. figs. 2—26).

Testa valde insequilateralis, crassiuscula, oblique ovata, postice paulo augustata,
latere autico late arcuato, postico subacute rotundato. Valvas probabilitor albidse,
epidermideque hirsuta amictae, striis teuuibus uumerosis radiantibus aliisque couceutricis
decussatse. Area ligameuti profuuda, excavata. Dentes cardinis numerosi, cii'citer 20—2-1.

This is a larger and more solid species than LimopsU straminea, and ditfers from
it also both in form and sculpture. It is not dilated posteriorly like that form, but ou
the contrary is even faintly pointed oi- at all events more sharply rouniled. The
sculpture is much stronger, and the hinge-teeth are more numerous.

Length 28 mm., height 22, diameter 12.

Habitat. — Station 145, Marion Island, in 140 fathoms, and Prince Edward Island,
in 100 to 150 fathoms.

Ail the specimens of this species which were oljtained are old dead valves, and in
poor condition, but retain sufficient of their character's for description.

Limopsis pelagica, u. sp. (PI. XVIII. figs. 3— iJa).

Testa forma habitixqiie Limoj)sis marionensis sed sculptura dissimilis. Valv;B autice
et in medio striis punetatis teuuibus radiantilnis, postice liris tenuissimis elevatis incre-
menti lineis decussatis ornatfe. Ej^idermis pallide olivacea, tenuiter fibrosa.

This species closely resembles Limopsis marionensis in form, the character of the
hinge, the ligamental area, and the interior of the valves, and is mainly distinguished by
a difierence of sculpture. This consists of numerous shallowly pitted radiating lines
which develop behind into slender lii-se, decussated by the concentric lines of growth
which are more elevated here and in front than vxpon the central jiortion of the valves.
The epidermis consists of very fine short pale olive fibres, which are very closely set
around the outer margin, forming a dense, soft fringe.

Length 22 mm., height 20, diameter 9^.

Habitat. — Station 106, Mid Atlantic, depth 1850 fathoms ; also Station 232, off
Inosima, Japan, at a depth of 345 fathoms.

A single shell from the latter locality, dredged without the animal, I can in no way
distinguish from those obtained at a depth of 1850 fathoms in Mid Atlantic. This is
another instance, of which several have abeady been recorded, of shells found in Japanese
waters being identical with those inhabiting the Mediterranean and Atlantic Oceans.

This species is very like Limopsis aarita, and may he only a large thin form of it.

REPORT ON THE LAMELLTBRANC'HIATA. 255

lAmopais .itraminea, ii. sji. (PI. XVTTl. figs. 5— 5a).

Testa peroblique ovata, inseqiiilateralis, sulx-ompressa, alba, nitida, epirlermide
fil)rosa straminea plus miuusve induta, incremeuti liiieis striata, striis radiantibus
pimctatis s(!ulpta. Mavgo valvarum uudique convexus, acutus. Latus anticum angus-
tum, posticimi latum, dilatatum. Dentes cardiuis circa duodecim, insequales. Pagina
interna lactea, prope lineam pallii radiatim substriata. Area ligamenti parva.

This is an oblique species, irregularh^ ovate, liroader behind thnn in front, having
all the margins more or less convex. The hinge-line, however, is almost rectilinear, and
the front portion of the ventral outline, which ascends obliquely, is rather straight. The
A^alves are very inequilateral, thinnish, pure white, and clothed to a great extent with a
straw-coloured fibrous epidermis. The umbones ai-e elevated a little above the hinge-
line, are devoid of epidermis, and are slightly separated. The sculpture consists of fine
radiating strias, which are in a great measure interrupted liy the concentric lines of
growth, and have on this account a somewhat punctate appearance. The interior is
milk-white, dull at the centre of the valves and glossy towards the margin, and exhibits
uumerous substri^e directed from the pallial line towards the umbones. The hinge-
plate is thinnish, and armed with about a dozen unequal denticles.

Length 20 mm., height 15;j, diameter 8.

Habitat. — Station 150, between Kerguelen and Heard Islands, at a depth of 150
fathoms ; coarse gravel.

Limopsis torresi, n. sp. (PI. XVIII. figs. 4— 4a).

Testa parva, convexa, leviter obliqna, altior quam longa, alba, costis concentricis
(irassiusculis, lirisque tenuibus radiantibus cancellata. Margo dorsi rectus, brevis ;
umbones parvi, supra marginem parum producti; linea cardinis mediocriter angusta
dentibus cii-citer octonis in medio interruptis instructa; pagina interna subnitida,
obsolete radiatim striata, margine externo intus deuticulato.

This is a small, rather convex shell, higher than long, obliquely roundish, white
and finely cancellated by fine concentric ribs, and as a nde rather finer radiating lirse,
the points of contact becoming a trifie thickened or subnodose. The beaks are small, not
quite contiguous, and just a little elevated above the dorsal line, which is short and
straight. The hinge-plate is not particularly broad, and is furnished with about eight
denticles, there being four on each side of a small central smooth space. The interior
is not very glossy, exhibits more or fewer radiating striae, and has the outer margin,
especially the lower part, denticulate wathin.

Length 3^ mm., height ^^, diameter 2j.

Habitat. — Station 185b, Raine Island, Torres Straits, in 155 fathoms; coral sand.

256 THE voYA(;i<: of h.m.s. challenger.

Limopsitt caucdluta (iJeeve).

Pectunculus cancellatus, Reeve, L'uiicli. Icon., vol. i. lig. 39.

Limopsis woodwardi, A. Adams, Proc. Zool. Soc. Lond., 1S62, p. 231.

Limopsis pMlippii, A. Adams, op. cit., p. 230.

Habitat. — Flinders Pas.sage, Station 186, AVednesday Island, Cape York; and Station
188, in 28 fathoms (Challenger); Singapore (Reeve); Lizard Island, Torres Strait (Adams).

After a careful study of the above so-caUed species I cannot Hud any good reasons
for their separation. The small difference in form is of little importance, as all the
species of this genus appear to l)e more or less variable in this respect. Tlie sculpture
of aU three is essentially the same, and the hinge-teeth, about twent5'-two in numl)er,
and the ligamental pit are quite similar in all. The inner edge of the valves is smooth
and flattened, the extreme outer edge Ijeing minutely crenulated by the external ridges.
The epidermis is finely pilose, and in concentric fringes.

Limopsis bassi, n. sp. (PI. XVIII. figs. 6— 6a).

Testii Limojisidi canceJlatcB similis, sed major, niagis obliijua ct trausver.sa, dentibus
minus numerosis raunita, iutus et extra plus minusve fusco tincta.

This species has a clathrate exterior like that of Limopsis canveUata of Reeve, but
may be distinguished by its more transverse and ol)lique growth, which appears to 1)6
constant in the good series of specimens at hand. It is also a larger shell, and, when
the thick pilose epidermis is removed, is seen to be stained with a reddish -lirowu tint,
except towards the umbones. The hinge -teeth are only aliout fifteen or sixteen in
number, or six or seven fewer than in LAmopsis canccUata, and that too, a smaller form.
The striated interior and the smooth flattened outer margin are alike in both species,
except that the latter in Limopsis bassi is usually tinted with reddish -lu-own.

Length 22 mm., height 18, diameter 9.

Habitat. — Station 162, off' East Moncoeur Island, Bass Strait, in 38 fathoms; sand
and shells.

To show the variation in form, I give the following dimensions of another unusually
long specimen : — length 20 mm., height 15 J, diameter 8i.

Limojisis brazievi, Angas.

Limopisis hrazieri, Anga.«:, Proc. Zool. Soc. Lond., 1S71, I'p. 21, 101.
Habitat. — Port Jackson, in 2 to 10 fathoms.

I have not much to add to Mr. Angas' description of this little species, but nia}-
observe that the fine concentric ridees are seen under a strong lens to be somewhat

REPORT ON TITE LAMELLTBRANCHIATA. 257

crenulated, and that the iDaigiii of the \alves is smooth and Hattoned witliin. The
shell is a little inequivalve, the anterior end or that towards which the beaks incline
being shorter than tlie posterior. The hinge-teeth are few in niunber, about three or
four on each side the central triangular deepish ligamental pit.

Limopsis anrito (Brocchi).

Area anrita, Brocelii, Conch. Foss. suL-app., vol. ii. p. 485, pi. xi. %. 9.

Pedunculus auritus, Philippi, Eiiuin. Moll. Sicil., vol. i. p. 63, vol. ii. p. 45.

Limopsis anrita, Jeffreys, Brit. Conch., vol. ii. j). 161, pi. iv. fig. 3, vol. v. p. 174, pi. xxx. fig. 1.

Limopsis aurita, Jeffreys, Proc. Zool. See. Loiul, 1879, p. 585.

Habitat. — Station 73, west of the Azores, in 1000 fathoms; Station 56, otf
Bermudas, in 1075 fathoms; Station 23, off Sombrero Island, West Indies, in 450
fathoms.

Limcypsis cumingii, A. Adams, associated by Jeffreys with this species, besides
being very different in form, has the teeth in a greater curve, and a peculiar lunular
excavation on the longer dorsal slope just in front of the anterior teeth. Limopsis
minuta and the present species appear to be very much alike, the former l)eing smaller,
with the inner margin of the valves crenulated, but whether this lie a good specific
character in this genus appears to me at present rather doubtful.

Limopsis lata, n. sp. (PI. X^'III. hgs. 7 -7 a).

Testa paulo oblicjua, late subovata, griseo-albida, epidermide fibrosa, prajcipue prope
marginem amicta, liris concentricis et radiantibus tenuibus cancellata. Margo dorsi
mediocriter elongatus, rectus. Latus anticum oblique curvatum, posticum minus
arcuatum," vix truncatum. Area ligamenti fuscesceus, anguste elliptica, concava, in
medio ligamento parvo augulato saturate brunneo instructa. Denies cardinis circiter
8—9 validi. Pagina interna rugosa, subpunctata, mai'ginc creuulato, subdentato,
incrassato.

This, judging from the series of specimens at liand, is a small species. It is
moderately thick and ventricose, somewhat oblique, of a dirty whitish coloui", and more
or less covered with an epidennis wliicli towards and upon tlie outer margin is rather
coarsely fibrous. The sculpture consists of fine radiating and concentric lii'ic, producing
a cancellated surface. The hinge-margin of course is straight and rather long. The
anterior side is Ijroadly curved and very o])lique below the middle, the posterior ])eing
less regularly arcuate and in some examples somewhat truncated. The um})ones are

(zool. chall. EXP. — PART XXXV. — 1885.) Mm 33

258 THE VOYAGE OF H.M.S. CHALLENGER.

afute when not eroded at the tips as is frequently the case, and located a trifle in
advance of the middle. The dorsal area is narrow, elongate-elliptical, rather deeply
concave, of a light brown colour, and provided with a diamond-shaped central dark
brown ligament. The hinge-teeth are strongish, in an almost straight series, and
number about eight or nine, of which two or three more are on the anterior side of the
beaks than behind. The interior of the valves is dull whitish, rather roughish,
exhibiting a kind of shallow pitting or subjxmotation. The outer margin is thickened,
distinctly dentate interiorly, and crenulated at the sides.

Length 8^ mm., height 8^, diameter 4f.

Habitat. — Station 169, off the north-east coast of New Zealand, at a depth of
700 fathoms.

This little species is peculiar for its width, comparative solidity, and dentate margin,
and bears considerable resemblance to Limopsis minuta.

Limopsis minuta (Philippi).

Pediinculus minuta, Philippi, Enum. Moll. Sicil., vol. i. p. 63, pi. v. figs. Scr, 3ft, vol. ii. p. 45.
Limopsis minufa, Siirs, Moll. Eeg. Arct. Norv., p. 44, pi. iii. figs. 5, a-c.
Limopsis minuta, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 585, pi. xlvi. fig. 9.

Habitat. — Station II., off east coast of Portugal, in 470 fathoms; Station 75, Fayal,
in 450 fathoms; Tenerife, in 70 fathoms; Station VIII., Canary Islands, in 620 fathoms;
and Station 24, off Culebra Island, West Indies, in 390 fathoms.

For the synonymy and distribution of this species consult the above paper by Dr.
Gwjm Jeffreys. I agree with him in considering Limo^jsis abyssicola, A. Adams, the
same as this species, but do not think that Limopsis cumingii of that author is
conspecific with Limopsis aurita, Brocchi.

Subfamily Arcing.

Area, Linne.

Area noce, Linne.

Area nocB, Linn^, Syst. Nat., ed. 12, p. 1140.

Area noce, Eeeve, Conch. Icon., vol. ii. pi. xi. fig. 72.

Habitat. — Station 36, off Bermuda, in 32 fathoms.

This well-known Mediterranean and West Indian species in the very young state
has at times the posterior side deeply notched.

REPORT ON THE LAMELLIBRANCHIATA. 259

Area navicular U, Bruguiere.

Area navicularis, Bruguiere, Ency. M^th., Vers., vol. i. p. 99, No. 4.
Area navicular^!, Philippi, Abbild., vol. ii. p. 210, pi. iii. fig. 2.
Area navieularis, Eeeve, Conch. Icon., vol. ii. pi. xi. fig. 70.
Area luwieulariii, Wood, lud. Test., pi. ix. fig. 5.
Var. = Area linter, Jonas, Philii)pi, op. cit., p. 209, tig. 1.
Var. = Area subquadrangida, Dunker, Philippi, op. cit., p. 210, fig. 3.

Var. = Area cumingii, Dvmker (MS. in Coll. Cuming), H. and A. Adams, Gen. Eec. Moll., vol. iL
p. .')33.

Habitat. — Cape York, North Australia, in .3 to 12 fathoms.

This species is also known as an inhabitant of the coast of Queensland, and has been
recorded from China and Amboina.

It is subject to miieh variation in form and in the amount of ligament in the
dorsal area.

Area imbricata, Bruguiere.

Area iwhrieata, Bruguiere, Ency. Meth., Vers., vol. i. p. 98, No. 3.

Area imbricata, Eeeve, Conch. Icon., vol. ii. pi. xi. fig. 73.

Area wnbonata, Lamarck, Anim. sans, vert., ed. 2, vol. vi. p. 462, No. 5.

Area wnbonata, Philippi, Abbild., vol. iii. p. 28, pi. iv. fig. 3.

Area euneiita, Eeeve, Conch. Icon., vol. ii. pi. xiii. fig. 87 (altered to Area cunealis in the

Index).
Area h-aussi, Philippi, op. cit., p. 88, pi. v. figs. 8-10.

Habitat. — Station 187, near Cape York, North Australia; and Station 113a, off
Fernando Noronba, in 25 fathoms.

There should be, one would think, and perhaps in reality there is, a difference
between the West Indian and Australian shells which appear to belong to this species,
but at present I am unable to discover it.

Area tetragona, Poli.

Area tetragona, Poli, Test. Sicil., vol. ii. p. 137, pi. xxv. figs. 12, 13.

Arcn tetragona, Forbes and Hanley, Brit. Moll., vol. ii. p. 234, pi. slv. figs. 9, 10, and PI.

P. fig. 1.
Area tetragona, Jeffreys, Brit. Couch., vol. ii. p. 180, and vol. v. pi. xxx. figs. 6-6a.

Habitat. — Station 75', off the Azores, in 450 fathoms.

This weU-known species has pi'cviously been recorded from the Azores and other
parts of the Atlantic.

200 THE VOYAGE OF H.M.S. CHALLENGER.

Arc(( (Barbatia) fusca, Bruguiere.

Arcafusca, Bruguifere, Ency. M^th., Vers., vol. i. p. 102.
Area fusca, Reeve, Conch. Icon., vol. ii. pi. xii. fig. 82.

Habitat. — Kandavu, Fiji Islands.

This species has been already recorded lioni the Mauritius, the Seychelles, and a few
other localities in the Indian Ocean, and is also found on the northern and western
shores of Australia.

Area (Barbatia) fasciata, Reeve.

Area fasciata, Reeve, Conch. Icon., vol. ii. pi. xv. fig. 99.
Barbatia fasciata, Aiigas, Proc. Zool. Soc. Lond., 1867, p. 931.

Habitat. — Port Jackson, New South Wales, in 2 to 10 fathoms.

The ligamental area is very deeply channelled in this species, which at times attains
a length of 2 inches.

Area (Barbatia) lima, Reeve.

Area lima, Reeve, Conch. Icon., vol ii. jil. xv. fig. 101.

Habitat. — Station 208, off the Island of Luzon, Pliilijjpines, in 18 fathoms ; and
Station 186, off Cape York, North Australia, in 8 fiithoms (Challenger); Islands of
Burias and Corrigidor, Philipj^ines, under stones at low water (Cuming).

This species is more inequilateral than Area fasciata from the New South Wales
coast, and is not " light brown, stained with brown, and spotted with brown " as stated
by Reeve, but is totally white both within and without beneath the epidermis ; that
species, on the contrary, being, for the most part, with the exception of a very broad
triangular space down the central portion of the valves, stained with a rich brown tint,
which is most conspicuous within the valves. The three small specimens from the
above locality show that this species (like several others), in the earlier stages, has the
posterior side more concave than when adult.

Area (Barbatia) raJula, A. Adams (PI. XVII. tigs. 3—36).

Area radula, A. Adams, MS. in Coll. Cuming.

Testa transversa, convexa, iua3(|uilateralis, antice rotundata, postice oblique curvatim
truncata, albidn, plus minusve fusco tinctn, liris radiantibus tenuibus confertis, minute

REPORT ON Tin: LAMELLIBRANCHIATA. 261

gnuiulatis, undiqvie instrurta, .stni.s(|uo iiicreiueiiti ;L'([ualiter coiifeiti.s sculpta,
epidermide fi))rosa margiuem versus iiiduta. Area dorsalis angusta, hand profunda.
Ligamentum laiicculatuin, jileruiiKjue hand ante umlioiies productum. Pagina interaa
albida, fusco tincta, vel [nupureo-Fusca. Umbones pauIo promiuentes, iucurvati, cin-iter
in ^—^ longitudinis colloeati.

Like many species of this genus, tliis is rather irregular in form, some specimens
being longer in proportion than others, and rather different in outline. They are for
the most part fairly convex, very inequilateral, rounded at tlie anterior end, and
oblicjuely, but curvedly, truncate behind. The ventral margin is somewhat parallel with
the hinge-line, at times exhibiting a slight median sinuation. The valves are not
very solid, sculptured with very numerous radiating and concentric strise, with very
slender granular ridges or lira^ between them, and clothed towards the outer margin
with a brown fibrous epidermis. The colour is variable, some specimens being wliitish
and faintly tinted with pale brown, whilst others are more uniformly brown. The
umbones are moderately prominent, about one and a half millimetres apart, and some
distance in advance of the centre. The ligamental area is narrow, and imly a little
sunken, the ligament usually extending from the posterior end to a little Ijehind the
beaks, where it is truncated. The interior varies in colour from whitish, more or less
stained with brown, to a uniform purple-brown. The hinge-teeth are small and
numerous.

Length 31 mm., height IS, iliameter 16.

Habitat. — Station 162, otf East Moncoeur Island, Bass Strait, in 38 fathoms (Chal-
lenger); Hudson's Bay, Port Pliilip, Sdutli Australia, attached to sea-weed, in 4 J
fathoms (Brit. Mus.).

The Challenger specimens and those in the British .Museum from the latter
locality are precisely similar in every respect, but differ slightly in one or two points
from those in the Cumingian collection, also said to liave come from Port Philip.
These are much darker coloured within, Avhich probably in this instance is not a very
important distinction, as they appear to be slightly diseased, and the ligament extends
somewhat in front of the umbones, whilst in the Challenger shells and the others fi-om
Port Philip it is suddenly truncated a little behind them. This, I think, is probably
due to age, for the two types in Cuming's collection appear to l)e older shells than
the others under examination, and the largest of tlie latter shows a slight tendency to
prolong the ligament more forward than it is in 3'ounger specimens.

Notwithstanding these difterences, I believe that they all l)elong to one and the
same species. Area jmrm, Sowerby, from Ducie's Island, is an aUieil form, differing in
being a little narrower, more finely sculptured, and in having the umbones rather
more remote from the centre.

2G2 THE VOYAGE OF H.M.S. CHALLENGER.

Area (Barhatia) scitlptilis, Reeve.

Area aculptilis, Reeve, Conch. Icon., vol. ii. jil. xvii. fig. 118.

Habitat. — Amboiua, in 15 to 25 fathom.s (C-hallenger) ; Island of Bohol, Philip-
jjines (Reeve).

This species is only a little inequilateral and somewhat stouter at the anterior end
than behind. The ventral margin is very feintly sinuated near, but just a trifle
posterior to, the middle, and the posterior end is obliquely truncate, the front margin
being arcuate. The ligamental area is a little excavated, exhibiting a small diamond-
shaped ligament between the over-curving beaks. The surftxce of the valves is finely
clathrated, the points of intersection of the radiating and concentric lirse being finely
nodose. The radiating ridges display a tendency to be alternately fine and coarser,
especially towards both ends of the shell, which in a fresh condition may be described as
whitish beneath a thin dirty brownish epidermis.

Area (Barhatia) pteroesm, n. sp. (PI. XVII. figs. 4—46).

Testa parva, tenuis, valde ingequilateralis, transversa, subcompressa, antice angustata,
acuminata, postice dilatata, oblique truncata, sordide albida, epidermide fibrosa laciniata
pallide fusca amicta. Yalvas ajquales, in medio im^Jressione baud profunda ab umboni-
bus radianti constrictse, liris radiantibus tenuibus aliisque concentricis flexuosis concinne
cancellatse. Umbones parvi, acuti, hand approximati, circiter in ^ longitudinis positi.
Ai'ea ligament! angusta elongata adamantiformis, postice angustata. Margo ventris
obHquus, antice ascendens, prope medium leviter sinuatus. Pagina interna alba. Linea
cardinis gracilis, dentibus circa octodecim miuiita.

This is a small thin species, veiy inequilateral, narrowed and pointed in front, much
dilated and oblicpiely truncated behind at the upper part, and rounded below the
truncation. It is dirty whitish, and covered, except at the apices, with a fibrous pale
brown epidermis disposed in concentric and overlapping fringes, and produced beyond
the edge of the valves. These are rather compressed, and marked with a slight depres-
sion which radiates from the umbones to the ventral margin, a little in advance of the
middle. The rectilinear dorsal line does not occupy the entire length of the shell.
The anterior side is very short, almost at once curving into the obliquely upward-
directed ventral margin, which is slightly sinuated at the termination of the oblique
depression down the valves. The sculpture consists of fine radiating liras, which are
interrupted by numerous, flexuose, concentric ridges or lines of growth, together
imparting a somewhat cancellated appearance to the surface. The beaks are only a

REPORT ON 'IHE LAMELLIBRANCHIATA. 263

little raised abuve the duisal margiu, rather ai-ute, and about a millimetre apart. The
ligamental area is elougate diamond-shaped, much narrowed and produced posteriorly,
and exhibits traces of a black ligament in the form of two slender lines, converging to a
point from the umboues towards the hinder extremity. The hinge-plate is very slender,
and armed with about eighteen teeth, whereof eight are in front of the apices, the
remainder behind them being ol)lique, and separated from the others by a short non-
dentate portion of the hinge-margin. The interior of the valves is white and only the
least glossy.

Length 11 mm., height 6|, diameter 4.

Habitat. — Station 246, Mid North Pacific Ocean, at a depth of 2050 fathoms ;
bottom, grey ooze. Also Stations 71 and 73, west of the Azores, in 1675 and 1000
fathoms respectively ; and finally, Station 24, off Cnlebra Island, West Indies, in 390
fathoms.

I have already recorded an instance of a species from very deep water in the
Atlantic, w^hich is all Init identical with another from a still greater depth in the Pacific
{vide Ccdlocardia atlantica and Callocardia 'pacifica), but here in this instance I am
unable to distinguish the examples from these two oceans. Such a distribution is an
eminently perplexing fact, a problem difficult of true explanation.

Area (Barbatia) corpule7ita, n. sp. (PI. XVII. figs. 5—56).

Testa tenuis, globosa, iuiuquilateralis, obliqua, altior (|uam longa, all)ida, epidermide
tenui olivaceo-fuscescenti, subfibrata iuduta, lineis, elevatis radiantibus filiformibus
aliisque concentricis minute cancellata. Umbones magni, iuflati, involuti, baud
approximati, latus anticum versus inclinati. Ai'ea dorsalis angusta, longitudinem testae
fere sequans. Ligamentum lineare, nigrum, post umboues positum. Latus anticum
late, aliquantoque irregulariter arcuatum, posticum subrectum. Margo ventris
semicircularis, antice oblique aclscendens. Pagina interna alba, confertim et radiatim
subpunctata. Linea cardinis angusta, dentibus irregularibus (in medio subobsoletis)
utrinque armata.

This remarkable species is very thin, much inHated, oldique, truncate-ovate,,
inequilateral, white, and covered with a thin olive-brownish more or less hairy
epidermis. The sculpture consists of very numerous, excessively fine concentric hair-
like lirce which are crossed by others as close and fine or even more slender which
radiate from the umbones, together forming a minute cancellation, the points of contact
being raised into minute tubercles from which arise the ejaidernial haii's. One of these
radiating lines, on the right valve only (the corresponding place in the left being
marked by a faint depression), is twice as thick as the others and located on the

26-t THE VOYAGE OF H.M.S. CHALLENGER.

posterior side, marking oft' as it were a dorsal area. The umboiies are very promiueut,
much inflated, well curved over towards the front, and a little remote from one another.
The anterior outline is oblique, In-oadly and somewhat irregularly arcuate, there being a
slight bulge near the upjier extremit}-. The posterior side is straighter, very faintly
sinuated liy tlie radiating depression, and regularly rounding beneath into the ventral
margin, which- is obliquely subsemicircular. The dorsal area is narrow, broadest in front
of the ])eaks, gradually attenuating posteriorly. It has the central line elevated
anteriorl}", and sunken at the opposite end beneath the ligament. This is small and of
course narrow, bounded on each side by the acute raised edges of the area, of a black
colour, and located in a few parallel grooves forming a much elongated diamond-shaped
figure. The hinge-line is slender, almost equalling the shell in length, and armed with
a few rather irregular teeth, at times more or less obsolete near the centre. The
interior of the valves is white, and on account of the thinness of the shell partly exhibits
the character of the external sculpture, and is more or less radiately faintly punctate,
the rows of minute feeble pittings corresponding with the lir^e of the exterior.

Length 20 mm., height 25, diameter 19^.

Habitat. — Station 184, east of Ca2)e York, Noi'tli Australia, at a depth of 1400
fathoms ; Station 194, south of Amboina, in 200 fathoms ; Station 198, oft" the north-
eastern extremity of Celebes, at a depth of 2150 fathoms; Station 216a, north-west
of New Guinea, in 2000 fathoms; Station 271, Mid Pacific, depth 2425 fathoms;
and finally. Station 300, near the Island of Juan Fernandez, off the Chilian coa.st, in
1375 fathoms.

This species is very unlike the typical forms of Barhatia, being far more globular,
of very thin substance, more finely sculptured, and clothed with a thinner epidermis.
There are, however, intermediate species which it more nearly resembles in some of the
above mentioned particulars, s(j that I think it may (at all events for the present) be
considered a very aberrant form of that group.

Area [Acar) congenita, u. sp. (PL XVII. figs. 6-6a).

Testa oblonga, crassiuscula, insequilateralis, antice angusta, oblique curvata, postice
latior, oblique truncata, superne inferneque angulata, albido-fuscescens, lamellis eoncen-
tricis, crassis, liris radiantiluis minus conspicuis crenulatis, sculpta. Valva? jjone
angulum cristatum al) umbone ad extremitatem posticam decurrentem concavse, in medio
leviter depressse. Umbones parvi, parum remoti, circa in f longitudinis coUocati. Area
ligament! angusta ; dentes ad sedecim utrinque ol)liqui. Pagina interna alba, subnitida.

This is a fairly solid little species, whitish l)rown, very inequilateral, of an oblong
form, narrow in front and gradually widening towards the posterior end, which is

REPORT ON THE LAMELLiBRANCHIATA. 265

obliquely truncate. The dorsal liue is not quite so long as the entire shell, owing to
the obliquity of the hinder side. The valves exhibit a very faint de[)ression down the
middle, which causes the ventral margin to have a slightly incur^^ed appearance at that
point, and at the posterior end, behind a prominent crested ridge or angle radiating
from the umbones to the lower hindmost extremity, they are conspicuously concave.
The sculpture consists of strong imbricating lamellse and radiating ridges. TJic former
are most conspicuous, frilled on crossing the ribs, and produced into short, hollow spines
on the posterior angle. The radiating ridges are about twenty-five to thii'ty in number,
most crowded a little in front of the centre, coarsest and farthest apart just in advance
of and iipon the oblique keel, from which those on the hinder concave surface radiate,
and not from the umbones like the rest. The ligameutal area is narrow, broadest
towards the front, and gradually tapering backwards, but not extending to the end of
the dorsal line. The umbones are small, hardly half a millimetre apart, curved over at
the tips, and situated at a])out two-sevenths of the entii-e length of the shell, from the
anterior extremity. The inner surface of the valves is white, a little glossy, showing,
indications of grooving, corresponding to the external sculpture, and on each side under
the hinge-plate the muscular scars, of whirh the posterior is the larger, are conspicu-
ously white and thickened. The hinge-plate is not very In-oad, and bears about sixteen
teeth, which are placed obliquely towards both ends ; and, under the microscope, appear
roughly striated.

Length 10 mm., height 5, diameter 5.

Habitat. — Station 201, off the west coast of Mindanao, Philippine Islands, in 82
fathoms ; stones and gravel.

This species is closely related to Area (loiningeusis, but may be at once distin-
guished by its.l)road truncate posterior end.

A7va (Acar) domingensis, Lamarck.

Area dominrjensis, Lamarck, Anim. sans vert., ed. 2, vol. vi. \k 467.
Area dominr/eims, Lischke, Jap. Mceres-ConcL, part ii. p. li'2.

Habitat.— Station 36, off Bermuda and 8t. Vincent, Cape Verde Islands, in ;]0

fathoms ; coral.

For the remarkable distribution of this species, and some interesting observations on
the synonymy, consult the above work by Lischke.

Area [Scapharca) angicostata, Reeve.

Area angicostata, Reeve, Conch. Icon., vol. ii. pi. i.^. tig. 57.
Habitat. — Station 212, south of the Island of Mindanao, Philippines, in 10 fathoms ;
sand.

(ZOOL. CHALL. ESP. — r.^KT .X.K.XV. — 18t>5.) ^Ini 3t

•2(SG THE VOYAGE OF H.M.S. CHALLENGER.

The locality of this species has not been hitherto recorded. The most slender ribs
are a few just in front of the centre of the valves, those on the anterior end being rather
stouter but not so thick as those down the posterior angle. Between the ribs are fine
concentric lirse which connect them and produce a slightly nodulose appearance and
somewhat crenulated edges. The interior of the valves is white, with the exception of a
small portion in the umbonal region, which is yellowish.

Area (Scapharca) clathrata, Reeve.

Area clathrata, Eeeve, Conch. Icon., vol. ii. ]>!. vii. fig. 48.
Habitat. — Torres Strait, in 3 to 11 fathoms; and Amboiua, in 15 to 25 fathom.-;
(Challenger); Islands of Burias and Ticao, Philippines (Eeeve).

The ribs in this species are about twenty-five in number, rather sharply cut at the
sides, and sej^arated liy deepish grooves. It is very closely related to Area radiata,
Reeve. The three small valves from Torres Strait are more like the t}"pes as regards
form than the single specimen from Amboina, which is narrower behind and more arcuate
below.

Area {Seapharca?) consociata, n. sp. -(PI. XVII. figs. 7-7o).

Testa ArccB clathratoe similis, sed costis tuberculis minoribus et rotundatioribus
ornatis, lineis incrementi in interstitiis magis remotis et curvatis, umbonibus in medio
hand impresse radiatis.

This species is very like Area clathrata, Reeve, in general aspect, but is, I believe,
distinct. The valves have no impressed ray near the beaks, the raised lines of growth
between the ribs are more curved and somewhat further apart than in Reeve's shell, and
the nodules are smaller, not so broad as the costaj, and more raised like minute half-beads.
At each end of the hiuge-line, and parallel with it, are two or three short, raised lines at
right angles to the teeth, which do not exist in Area clathrata.

Length 12^ mm., height 9|, diameter 8^.

Habitat. — Station 189, Arafura Sea, in 25 fathoms ; green mud.

The above dimensions do not probably represent the full size attained by this pretty
species.

Area {Seapharca) gubernaculum, Reeve.

Area gnbenmmlum, Eeeve, Conch. Icon., vol. ii. pi. iii. fig. 14.
Area clmhnnthum, Eeeve, loc. cit., pi. vii. fig. 4-3.
Area luzonica, Eeeve, loc. eil., fig. 44.

Habitat. — Port Jackson, in 2 to 10 fathoms.

REPORT ON THE LAMELLIBRANCHIATA. 207

Area chalcanthum is certainly ;i slightl}- .shorter form of tlii.s species, with which it
exactly corresponds iu all other respects. Both are said to have been obtained at the
Pliilippine Islands.

Area [Scapharcaf) incequisculpta, n. sp. (PI. XVII. figs. 8-8c).

Testa parva, oblique truncato-ovata, ventricusa, ina^qiiilateralis, alba, epidei'midc tcnui,
aliquanto fibrata, iuduta, concentrice radiatimque tenuiter lirata, cancellata. Latu.s
anticum obliquissime late arcuatum, posticum subperpendiculariter c-ur\atuiu. Margo
ventris subsemicircularis, antice oblique ascendens. Umbones vix promiuuli, parvi,
paululum remoti, haud acuti. Area dorsalis angusta, paulo impressa, margiuibus carinatis
prnecipue posterioribus circumdata. Dentes haud uumerosi, utrinque a medio divergentes.
Pagina interna all^a, in valva sinistra prope margiuem sulco punctato-denticulato ornata.

This species is about as high as long, obliquely ovate, truncate above, rather
veutricose, inequilateral, inequivalve, of a pure white colour, in fresh specimens more
or less covered with a thin and somewhat hairy epidermis. The valves are rather
glossy, thinnish, sculptured with fine concentric grooves and intervening raised lira;,
wliich are excessively fine at the sides and a little thicker at the middle. These are
crossed by other rather finer lirae which radiate from the umbones and produce a finely
cancellated surface. They are rather more elevated in the right valve than in the left.
The dorsal line occupies the whole length of the shell, the angles formed by its
conjunction with the sides being rather greater than right angles. The ventral outline is
very arcuate, ascending obliquely in front, and more suddenly behind, on which side the
margin is very slightly curved and almost perpendicular. The opposite is more arcuate,
and curves obliquely towards the base. The umbones are not large, only a trifle raised
above the hinge-line, not acute, a little remote from one another, and located at about
one-third of the entire length of the shell from the anterior end. The ligamental area is
narrow, somewhat broader in front of the beaks than behind them, a little sunken, and
bordered with carinnte margins, especially posteriorly. The hinge-teeth are not very
numerous, being about seventeen to twenty, divergent on each side of the centre.
The interior is white, in young specimens at times exhibiting more or less radiate
subpunctate grooving. In the left valve, just within the margin, there is a narrow
punctate and finely denticulated groove, which receives the margin of the op]iosite valve.

Length 8^ mm., height 8, diameter 6^.

Habitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

It is curious that in this species the radiating excessively fine lirse should be decidedly
more distinct and elevated in the right valve than in the left. It is closely related to
Area pectunculoides and Arcafrielei, but was pronounced distinct by the late Dr. Gwyn

268 THE VOYAGE OF H.M.S. CHALLENGER.

Jeflreys, wlio, with his accustomed eoui'tesy, kiudly examined tliis species, and showed
me tlie specimens of Arcafrielei figured in the Proc. Zool. Soc. Lond.

Area (Scapharca ?) culebrensis, n. sp. (PL XVII. figs. 9-9?>).

Testa transversa, valde inaequilateralis, antice angustata, postice dilatata, utrincpie
rotundata, alba, tenuissime cancellata, plus minusve granulata. Valvse tenues, semi-
pellucidse, impressione baud profunda ab umbonibus ad marginem ventralem paulo ante
medium leviter sinuatum signatse. Umbones parvi, parum prominentes, Isevigati,
subapproximati, circa in I longitudinis positi. Dentes circa 8, ntrinque divergentes, in
medio interrupts

This sj)ecies is very inecj^uilateral, longer than high, much narrower in front than
behind, where it may l^e said to lie dilated. Both extremities are rounded, and tlie
ventral margin, which ascends oblicpiely towards the anterior end, is faintly incurved a
little in advance of the middle at the termination of a shallow depression, which extends
from the beaks downwards. The valves are thinnish, semitransparent, white, and
sculptured with numerous very fine radiating and concentric Lirse, the points of inter-
section being, as frecjuently is the case, somewhat thickened, and on the posterior side
distinctly granulose. The umbones are not much raised aliove the dorsal line, situated
from one-fourth to one-fifth of the total length from the anterior end, and smoothish
at the tips, which are only a little apart. The hinge-plate is consideral)ly shorter than
the valves, and is furnished with about eight divergent teeth, of which three are in front
of a central edentulous space and five behind it, the whole series forming a nearly straight
line. Owing to the transparency of the valves, more or less of the external ornamentation
is visible within.

Length 5 mm., height 3^, diameter 2^.

Habitat. — Station 24, ofi" Culebra Island, West Indies, in 390 fiithoms ; Pteropod ooze.

This species is very like the variety septentrionalis of Area pectunculoides, Scacchi,
Ijut rather more oblique in growth, more sharply rounded behind, with the umbones
more anterior, &c.

Area (Trisis) semitorta, Lamarck.

Area semitorta, Lamarck, Anim. sans vert., ed. 2, vol. vi. p. 460.
Area semitorta, Eeeve, Concli. Icon., vol. ii. pi. xiii. fig. 89.

Habitat.— Torres Strait, 3 to 12 fathoms (Challenger); Port Essington (Brit. Mus.);
Zebu, Philippines (Cuming); Tasmania (Lamarck).

The last locality has not, I believe, been confirmed.

IIEPOKT ON THE LAMELUBRANCHIATA. 269

Arm {Macrodon) dalli, ii. sp. (PI. XVII. fig. 10-106).

Testa transversa, oblonga, vakle insequilateralis, antiee rotundata, postice obliquiter
arcuatim truncata, ad extremitatem acute rotundata, sordide alljida, epidermide fusco-
olivacea concentrice lamellata induta. Valvse mediocriter tenues, undique tenuiter liratae,
incrementique lineis sculptte. Pagina interna caeruleo-allnda, nitida, tenuiter radiatim
striata, margine externo vix crenulato. Area ligamenti angustis.sima, linearis. Linea
cardinalis dentibus paucis (circiter 8-10) infequalibus anticis, duobus posticis perelongatis,
margine dorsali piarallelis, instructa.

This species is very inequilateral, oblong, transverse, moderately convex, rounded in
front, obliquely curvedly truncate behind, and sharply rounded at the extremity. The
valves are not particularly thick, Ijut rather thin, dirty whitish, and covered to a great
extent with a brownish-olive epidermis which at short intervals is concentrically lamellated.
The sculpture consists of fine close-set radiating lirse and fine Hues of growth, some at
intervals, which mark the position of the epidermal lamella3, being especially conspicuous,
'i'he umbones are small, close together, not more than a millimetre apart, and situated at
scarcely a fourth of the whole length from the anterior end. The ligamental area is very
narrow indeed, the ligament being principally behind the Ijeaks in a groove on the hinge-
niargin. There are eight or ten denticles upon the anterior half of the hinge-plate, of which
the front ones are the largest, and at the posterior end are two or three elongated ones
parallel with the dorsal outline. The interior is bluish-white, exhibiting concentric zones
and radiating fine but distinct strise, except on the margin outside the pallial line.

Length 31 mm., height 18, diameter 12.

Habitat. — Station 233a, off Kobe, Japan, in 50 fathoms ; sand.

The posterior teeth are not so long as in the type of the section Macrodon, but still
quite diflerent from any other species of recent Arcidaj with which I am acquamted.

It is interesting to find this fossil form occurring in the Pacific Ocean, it having
already been recorded from deep water in the West Atlantic by Mr. Dall (Eeport Moll.
"Blake" Exped., 1877-79, p. 120), with whose name I have the pleasure of associating
the present species.

Family J r l 1 1 d m.

Julia, Gould.
Julia exquisita, Gould.

Julia exquisita, Gould, rroc. Boston Soc Xat. Hist. (1862), vol viii. p. 284.
Julia exquisita, Gould, Otia Conch., p. 241.

Julia exquisita, 0. Semper, Journ. de Conch., 1865, vol xiii. p. 297.

Prasina horhonica, Deshayes (1863), in ^Maillard's llr .!.• hi liruniuii, vol. ii. Annexe E, p. 29,
pi. iv. tigs. 4-8.
Te.sta minuta, oblonga, antiee producta, rostrata, autc umbones concave depressa,

270 THE VOYAGE oK II. M.S. CHALLENGER.

v;ilde iiuvquihiteralis, sordide alljidii, siilipellucida, crassiuscula, parimi couvexa, postire
rotundata, striis incremeuti minutis sculpta, lineisque albis conspicuioribus numerosi.s
radiantibus curvatis ornata. Margo dorsi auticus brevissimus, leviter concavus, declivis,
posticus elongatus, arcuatus, horizontalis. Margo veutris parum convexus, antice lente
ascendens. Umbones couspicue antrorsum involnti, baud coutigui, iu :|; lougitudiuis
collocati. Linea cardinalis pone umboues arcuata, in valva sinistra sulco elougato arata,
dente unico crassissimo ab apice fossa profunda separato munita. Pagina interna
uitida, striis radiantibus notatis. Cicatrices et linea pallii baud conspicuae.

Only two left valves of this curious little sbell were obtained. Tbej" are very inequi-
lateral, the anterior side being very short, acuminated or beaked, the posterior on the
conti'ary terminating in a broadly rounded extremity. They are thickish in substance,
suljpellucid white, not very convex, rather deeply concave in front of the umbo. They
are sculptured with very minute strijB of growth, and one of them is further ornamented
with numerous curved radiating lines which appear opaque-white upon a somewhat
diaphanous ground, and are closer together down the posterior half of the surface than in
front. The anterior part of the doisal line is very short, oblique, and slightly concave,
the posterior, on the contrary, being long and horizontally curved. The ventral or lower
outline is scarcely at all excurved, and gently ascends towards the front. The umbo is
remarkably curved over anteriorly, and being also directed at the tip away from the
dorsal edge, would not touch that of the opposite valve when closed. The hinge-plate
behind the beak exhibits a long, slightly curved groove for the reception of the ligament,
and a single very strong tooth, cleft at the top, rests upon the anterior part (beneath the
umbo), which is separated from the posterior portion by a deep broad concavit3^ The
interior is glossy and marked with the external radiating lines. Neither the muscular
scars nor the pallial line have been discovered.

Length if mm., height 1^, probable diameter of complete shell

Habitat. — From the Reefs off Honolulu, Sandwich Islands, at a depth of 40 fathoms
(Challenger) ; Sandwich Islands (Gould) ; Reunion or Bourbon (Deshayes).

One of the two valves obtained at this locality is destitute of the radiating white
lines, and is less acutely beaked in front. Excepting the absence of the green colour, so
characteristic of this curious shell, the presence in one instance of more numerous radiating
white lines and the small size (due probably to difference of age) there does not appear
at present any sufficient reason for considering the valves described above as specifically
distinct. The want of colour may be the result of fading, and the extra acuteness of
the rostrated end in one of the valves an unusual variation, as neither in Deshayes' figure,
nor in specimens in the British Museum, does this part appear quite so acuminate.

The true systematic position of this curious genus has yet to be determined. Gould
associated it with Pedum and Vulsella, whilst Deshayes placed it with the Mytilidse.

REPORT UN THE LAMELLIBRANCHIATA. 271

Family M Y t 1 1. 1 d .-e.
Subfamily Dreissenin.^.

Sejitifc'i-, Recluz.

Septifer h'docularis, (Liune).

Mytilus hilocidaris, Linn6, Syst. Nat., ed. 12, p. 1156.

Mytilus hilocidaris, Wood, Ind. Test., pi. xii. fig. 17.

Mytilus nicoharicus, Chemnitz, Concli.-Cab., vol. viii. p. 155, pi. Ixxxii. figs. 736, a, h.

Ticliogonia bilocularis, Kiister, Conch. -Cab., ed. 2, p. 10, pi. ii. figs. 11-17.

Tichoijonia wiefjmanidi, Kiister, luc. cit, p. 11, pi. ii. iigs. 6-10.

Tichogonia Jcraussii, Kiister, loc. cit., pi. vi. iigs. 1-6.

Septifer bilocularis, Recluz, Rev. et Mag. Zool., 1848, p. 278.

Septifei- hilocidaris, Recluz, Rev. et Mag. Zool., 1849, vol. i. p. 125.

Septifer hilocuhiris, Martens, iloll. INlauritius, p. 318.

Mytdus nicoharicus, Reeve, Conch. Icon., vol. x. pi. ix. fig. 42.

Mytihis pdosiis (Recluz, MS.), Reeve, loc. cit., pi. viii. fig. 35.

Septifer cuniingii, Eccluz, Rev. et Mag. Zool., 1849, vol. L p. 132.

Mytilus cunnngianus, Reeve, loc. cit., pi. xi. fig. 52.

Habitat. — Off Le\'nka, Fiji, in 12 fathoms.

The small shells described by Recluz as Septifer cumingii should not, I think, be
separated from this species. They are said by Reeve (who wrongly quotes the species
both orthographically and as undescribed) to have come from Panama, and Recluz gives
their locality as " les cotes de I'ile Annaa (pres le detroit de Panama), dans Toc^an-
Pacifique." I have not been able to discover any island of that name near Panama, the
only Annaa Island with which I am acquainted being situated in the Low Archipelago,
east of Tahiti.

Many shells were collected b)^ ]\'Ir. Cuming at the " Island of Annaa, Pacific Ocean/'
judging from Reeve's Conchologia Iconica, where it is very often mentioned. It therefore
seems to me probable that the Septifer cumingii was collected at the same island in
the Mid South Pacific and not in the Panama region.

Some minute shells were identified with this species by Carpenter (Mazatlan Cat.,
p. 120), and it is subsequently stated to be "common" at Cape St. Lucas, California
{vide Moll. West. North America, 1872, p. 106).

After a careful comparison of the types of Septifer cumingii and Septifer pilosus
with specimens of Septifer bilocularis, I am unable to discover any sufficient grounds for
separating them sjjecifically.

This species seems to be widely distributed throughout the Indian Ocean and in
many parts of the Pacific.

272 THE VOYAGE OF H.M.8. CHALLENGER.

Subfamily Mytilin.e.

Mytilus, Linne.
Mytilus edulis, Linne.

Mi/tiliis edtditi, Linne, Syst. Nat., ed. 12, p. 1157.
Habitat— 8t(itioD. 322, off the Rio de la Plata, in 21 fathoms ; Station 315, Falkland
Islands, in 12 fathoms; and D'Urville Island, New Zealand.

This common species has become widely distriliuted, and differs considerablj' in form,
colour, and size. Hutton quotes it as occurring in New Zealand, and I have already
identified it as coming from Kerguelen Island (Phil. Trans. Roy. Soc, 1879, vol. clxviii.
p. 189).

Mytilus imujellanicus, Chemnitz.

Mytilus magellankus, Chemnitz, Concli.-Cab., vol. \-iii. pi. kxxiii. fig. 742.
Mytilus magellanicus, Eeeve, Conch. Icon., vol. x. pi. vi. fig. 22.
Mytilus wagellanicus, Smith, Phil. Tran.s., 1879, vol. cLxviii. p. 188.

Habitat. — Station 315, Falkland Islands, in 12 fathoms; Betsy Cove, Kerguelen
Island, on the shore ; and Kandavu, Fiji.

A single small .specimen from the last locality is apparently inseparable from this
weU-known species, which is also met with on the shores of New Zealand.

Mytilus exustus, (Lamarck) Reeve.

Mytilus exusfux, (Lamarck) Keeve, Conch. Icon., vol. x. p1. iv. fig. 10.

Habitat. — Station 113a (?), St. Michael's Rocks, Fernando Noronha ; and Station
122, off Pernambuco, in 350 fathoms.

The specimens from these localities belong to Mytilus exustus as identified by Reeve,
but until an opportunity occurs of studjang aU the shells belonging to this striated
group of Mytilus, it is impossible to say whether the species should or should not
definitely retain this name. Mytilus cubitus of Say, Mytilus variabilis of Krauss, and a
few other forms appear to be so very closely related that it would be hazardous to
pronounce them either di.stinct or conspecific without a much longer study than I can at
present bestow upon them.

Mytilus sulcatus, (Lamarck ?) (Reeve).

Moiliola sulcata, (Lamarck) Reeve, Conch. Icon., vol. x. pi. x. fig. 74, sp. 61.
Habitat. — Wednesday Island, near Cape York, North Australia.

REPORT ON THE LAMELLIBRANCHIATA. 273

A uiiml)er of dead valves, all that was obtained, undoulttedly Itelong to this species as
figured by Reeve. There are iu the British Museum also other specimens from the coast of
Australia, and another series from Jamaica appears all but identical, but the dorsal angle
in these specimens is more prominent, the sinuatiou in the outline behind it is more
marked, and the radiating strise are continued feebly right to the anterior end, whilst iu
the Australian examples there is a slight interruption of them near that extremity.

Mytilus hii'sutus, Lamarck.

MijtiluK liirgutus. Lamarck, Reeve, Concli. Icon., vol. x. pi. Hi. fig. 8.
Mytilus hirsutas, Dunker, Ind. Moll. Japon., p. 222.

Mytilus (Aulacomya) hirsutus, Angas, Proc. Zool. Soe. Lond., 1865, p. 6-52.
Mytilus (Aiilacoiii ya) hirsutus, Angas, ojh cif., 1867, p. 928.

Habitat. — Port Jackson, Sydney, in 6 to 15 fathoms.

This species ranges from South Australia, also along the east coast, and as far north
as China and Japan. It is also said by Angas to have been found at New Zealand, but
this has not .since been confirmed.

Mytilus mevidionalis, n. sp. (PL XVI. figs. 3-3a).

Testa compressa, subovata, superne subacuminata, ad apicem obtu.sa, alta, allja, striis
increment! insculpta, prope umbones oljsolete radiatim costata. Margo dorsi utrinque
valde decli^ds, antice elongatus, postice brevior, minus obliquus. Cardo edentulus.
Ligamentum magnum, subinternum, in fossa elongata, haud profunda, latiuscula situm.
Pagina interna superne callosa, inferne tenuior, radiatim minute substriata, ad marginem
acuta, simplex.

This species is much flattened, higher than long, irregularly ovate, and somewhat
acuminate above. It is white, glossy, and striated ])y concentric lines of growth, some
of which are more strongly marked than others. It is also sculjiturcd with a few feeble
ridges which radiate from tlie beaks. The dorsal margins are almost straight but unequal,
the anterior being the longer and rather more sloping than the posterior. The uml)0 in
both the valves under examination is prominent, and terminates iu an ol)tuse apex,
surrounded as it were b)^ a thickened collar. In front of it iu the right valve there is a
narrow but very deep lunular excavation, and l)ehind, in a broad shallow elongate groove
on the toothless hinge-plate, is placed the ligament, which may be described as subexternal,
as it would be slightly visible when the valves were closed. The interior is thickened at
the upper part with a minutely rugose, dull, shelly deposit, becoming thinner as the lower
margin is approached, and displaying a faint radiate sul)striation. The pallial line and

muscular scars are indistinct.

(zool. chall. EXP. — PART xx.KV. — 1885.) Mm 35

274 THE VOYAGE OF H.M.S. CHALLENGER.

Length 5 mm., height 6, diameter 2f.

Habitat. — Station 150, between Kergueleu and Heard Iskinds, in 150 fathoms,
coarse gravel ; and off Prince Edward Island, in 100 to 150 fathoms.

The above is the supposed diameter of a complete shell, being double that of the
valve obtained at Station 150, which is presumed not to be adult. It may be only a
variety of Mytilus herguelensis, but its form is very different, and the radiating lines are
stronw-er and fewer.

Mytihis herguelensis, n. sp. (PI. XVI. figs. 4-4a).

Testa parva, solidiuscula, alba, epidermide liavescenti, hirsuta induta, incrementi lineis
striata, lirisque tenuissimis, radiantibus instructa, antice acuminata, postice dilatata.
Pagina interna alba, nitida. Linea cardinis crassiuscula, edentula.

This little species may be recognised by its white colour and the brownish-yellow,
hairy, or chafty epidermis. It is rather solid, concentrically and radiately striated,
narrowed in front and dilated behind. The dorsal outUne is arched without an angle,
the ventral being straighter. The interior of the valves is white and somewhat glossy.
The hinge-line is rather thick and toothless.

Length 8 mm., height 5, diameter 3^..

Habitat. — Station 149, Royal Sound, Kerguelen Island, on the shore.

The tips of the umbones in this species are also capped as in Mytilus meridionalis.

Mytilus (Stavelia) horridus, Dunker.

Mytilus Jwrridits, Dunker, Proc. Zool. Soc. Land., 18.56, p. 359.

Mytilus Jwrridus, Reeve, Conch. Icon., vol. x. fig. 9.

Mytilus tortus, (Dunker) Reeve, loc. cit., fig. 6.

Stavelia torta, Gray, Pioc. Zool. Soc. Lond., 1858, p. 90, pi. xli. ficjs. 1-1 a.

Habitat. — Station 186, off Cape York, North Australia, in 8 fathoms (Challenger) ;
Cape Capricorn, North Australia, and Island of Mindanao, Philippines (Reeve).

I agree with Gray in uniting the above species, but do not consider the sinuosity of
the ventral margin of generic importance. Reeve states that Dunker described Mytilus
tortus in Proc. Zool. Soc. Lond., 1856, but I only there find a mere reference to that name
by the latter author in his description of Mytilus horridus, and I have been unable to
trace any account of it in any other work. The Challenger shell is very large, being
6^ inches in length.

REPORT ON THE LAMELLIBRANCHIATA. 275

Modiola, Lamarck.
Modiola barhata (Linnd).

Mytilus harhatus, Linne, Syst. Nat., erl. 12, p. 1156.

Blijtilas harhatus, Jeffreys, Brit. Conch., vol. ii. p. 114, vol. v. pi. xxvii. fip. 3.

Mudiola barhata, Forbes and Hanley, Brit. ]\Ioll., vol. ii. p. 190, pi. xliv. fig. 4.

Habitat. — Station 2;33a, Kobd, Japan, in 50 fathoms sand.

The European Mytilus modiolus is ah'eady known as an inhabitant of Japane.se waters,
but this is, I believe, the first record of the occurrence of Modiola barhata, another well-
knowTi form on manj' parts of the coast of Europe.

Modiola capax, as figured by Reeve, is very closely related to, if not identical with,
this species.

Modiola glaberrima (Dunker).

Volsella glaherrima, Dunker, Proc. Zool. See. Lond., 18.56, p. 363.
Modiola glaherrima, Reeve, Conch. Icon., vol. x. pi. viii. fig. 48.
Perna glaherrima, Angas, Proc. Zool. Soc. Lond., 1867, p. 929.
Modiola glaherrima. Smith, Report "Alert" MoUusca, p. 108.

Habitat. — Port Jackson, Sydney, in G to 15 fathoms.

This species has not, I believe, been recorded from any other locality than the Sydney
district.

Modiola ivatsoni, n. sp. (PL XVI. figs. 5-5c).

Testa fragilis, subpellucida, albida, marginem dorsalem versus inferneque viridi tincta,
polita, incrementi lineis striata, pone umbones subfortiter corrugata. Valvae in medio
convexae, postice conipressaj, latge, areuatas, autice angustatas. Margo dorsi posterior
leviter convexus, ventrali medio levissime incurvato. Umbones parvi, approximati,
iridescentes. Pagina interna alba, parum nitida.

This species is very fragile, semitransparent, white, stained with pale olive-green
along the dorsal margin, and upon the lower portion of the valves. The valves ai-e
moderately convex at the centre and become compressed behind. They are very narrow
at the anterior end and sharply rounded, gradually widen posteriorly, and terminate in a
broadly arcuate end. The dorsal margin rises considerably behind, and is faintly convex,
the ventral, on the contrary, being feebly incurved.

The sculpture consists of fine concentric lines of gi-owth, and excessively minute
radiating lines, not incised striae. In addition to this, the dorsal surface for some distance
behind the umbones exhibits several plications or wrinklings. The bealcs are small,
incurved, somewhat iridescent, situated at a short distance from the anterior extremity.

27G THE VOYAGE OF H.M.S. CHALLENGER.

The interior is white aud not glossy, but this may not always be the case in specimens
found living, the only shells under examination having been dredged without the animals.

Length 43 mm., height 22, diameter 13|^.

Habitat. — Station 207, west of the Island of Luzon, Philippines, at a depth of 700
fathoms ; also Station 191, near the Arrou Islands, in 800 fathoms.

The specimens from the latter locality have not attained so large a size as the single
example from off the Philipjjines, the dimensions of which are given above. They are
not quite so gently arcuate at the posterior end, have the ventral outline sHghtly convex,
and exhibit a few distinct scratch-like striae across the anterior lower portion of the
valves at right angles to the lines of increment. In the type I also find a few traces of
similar striae.

This species belongs to that section of the genus which includes Modiola arhorescens,
Chemnitz, Modiola glaherrima, Dunker, Modiola degans, Gray, Modiola perfragilis,
Dunker, and a few others, characterised by light fragile shells with a highly glossy
surface. The last of the above-mentioned forms most resembles that now described. It
is, however, much narrower, has no dorsal plications or wrinkles, and is not quite so
fragile and iridescent within.

Both the large and small specimens of Modiola watsoni, so named in honour of my
friend the Eev. R. Boog Watson, have more or less of a rust-like incrustation adhering to
the anterior or umbonal region, which in the former has stained the surface yellowish -brown.

Lithodomtis, Cuvier.

Lithodomus antillarum (Philippi).

Modiola (Litlwphagus) antillarum, Philipiji, Zeitschr. Malakozool, 1847, p. 116.

Modiola antillarum, Philippi, Abbild., vol. iii. p. 20, pi. ii. fig. 4.

Lithodomus antillarum. Reeve, Conch. Icon., vol. x. pi. ii. fig. 7.

Lithodomus niger, d'Orbigny, in Sagra's Hist. Cuba, Molliisques, vol. ii. p. 331, pi. xxviii.

figs. 10, 11.
Lithophaga nigra, Dunker, Conch.-Cab., eJ. 2, p. 12.

Habitat. — Bermuda, boring in coral.

The Lithodomus antillarum described by d'Orbigny in the above work (p. 332)
appears to be identical with Lithodomus corrugatus of Philippi.

Lithodomus appendiculatvs (Philippi).

Modiola a.ppendiadida, I'hilippi, Abbild, vol. ii. p. 150, pi. i. fig. 4.
Lithodomus ai:>pemlicidatus, Reeve, Conch. Icon., vol. x. pi. iv. fig. 21.
Lithophaga appendiadata, Dunker, Conch.-Cab., eJ. 2, p. 15, pi. v. fig. 14.
Lithodomus hisulcatus, d'Orbigny, in Sagra's Hist. Cuba, MoUusques, vol. ii. p. 333, pi. xxviii
figs. 14-16.

Habitat. — Bermuda, boring in lioral {Ocidina hermudiana).

REPORT ON THE LAMELLIBRANCHIATA. 277

This species luis been recorded iruiii Cuba (Philipiii) ; Jamaica, Martinique,
Guadaloupe, and St. Domingo (d'Orbigny).

Lithodomus nudaccanus, Reeve.

Litliodomng maluccanit-i, Reeve, Conch. Icon., vol. x. pi. iv. li^'. 20.
Lithophaga malaccana, Dunker, Conch. -Cab., ed. 2, p. 20, pi. v. ii". I.

Habitat. — Station ISG, off Cape York, North Australia, in 8 fathoms.

The anterior end of this species is rounded, but the hiuder extremity of the shell,
which can only be seen when tlie valves are parted, is more truncate and only a little
arcuate. The interior is of a pale brown tint, and more or less iridescent.

Subfamily Crenellin/J';.

CretieUa, Brown.

Crenella marioneasis, n. s]i. (PI. XVI. figs. G-Qa).

Testa parva, tenuis, alba, nitida, paulo obliqua, subcordata, convexiuscula, superne
hita, inferne angustata, radiatim tenuiter lirata, liris incrementi striis decussatis.
Umbones rotundati, vix elevati, ad apices obtusi, semipellucidi. Linea cardinalis angusta,
minutissime transversim striata, in medio, infra umbonem fossa ligamenti curvata
transversa insculpta, prominentia dentiformi laterali postica in valva sinistra instructa.
Pagina interna subnitens, umbones versus minute subpunctata, inferne radiatim tenuiter
sulcata, ad marginem subtiliter denticulata.

This is a very thin, delicate species, white, glossy, and sculptured with numerous fine
radiating lirse which are scarcely raised at all and crossed by the concentric lines of
growth. This ornamentation is so fine that it is all Init invisible to the naked eye.
The form is oblique, somewhat cordate, rather convex, l)roader above towards the
umbones than at the lower end. The posterior side is regularly broadly curved in an
oblique direction, the anterior being more erect and straighter. The umbones are
moderately large, not much elevated, and terminate in a rounded semipellucid tip. The
liinge-plate is narrow, microscojjically transversely striated, has an elongate, narrow,
central ligamental groove and a single more or less distinct lateral tooth-like projection
on the hinder side in the left valve, and an indication of one in the right. The interior
of the valves under the microscope appears towards the uml>ones to be subpunctate,
and is finely striated towards the minutely dentate margin.

Length 4 mm., height i^, diameter 2f.

Habitat. — Station 145, ofi" Marion and Prince Edward l.-lands, in 140 fathoms.

278 THE VOYAGE OF H.M.S. CHALLENGER.

This is a more fragile species than the northern Crenclla decussata of Montagu, moi-f
shouldered above, more finely sculptured, and different in its hinge, but not sufficiently so
to warrant a generic separation.

Modiolaria, Beck.

Modiolaria lanigera (Dunker). \

Litlwdonius laniger, (Dunker MS.), Eeeve, Conch. Icon., vol. .x. pi. v. fig. .30.

Lithodomus harbatus, Reeve, loc. cit., fig. 27.

Modiolaria harhata, Angas, Proc. Zool. Soe. Lond., 1867, p. 911, pi. sliv. tig. 12.

Habitat. — Port Jackson, in 2 to 10 fathoms (Challenger) ; Sydney (Reeve) ; Botany
Bay, New South Wales (Angas).

I fail to appreciate the diiferences between the above species. Angus was evidently
misled by Reeve having described this shell as a Lithodomus.

Modiolaria cumingiana, Dunker.

Modiola cumingiana, (Dunker M.S.), Reeve, Conch. Icon., vol. x. pi. ix. figs. 6.3, a, h, sp. 50.
Crenella {Modiolaria) ciuinnijiana, Angas, Proc. Zool. Soc. Lond., 18G.5, p. 6.53.

Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms.

This species has also been found at Moreton Bay on the east coast of Australia (Reeve),
at Swan River on the west coast (British Museum), and at St. Vincent's Gulf, on the south
coast, amongst Zostera, in 1 to 3 fathoms (Angas), and finally in Mr. Cuming's collection
there is a pretty pink variety labelled as having come from the Red Sea.

Modiolaria varicosa, Gould.

Modiolaria varicosa, Gould, Proc. Boston Soc. Nat. Hist., 1861, vol. viii. p. 37 ; Otia Conch.,

p. 176.
Modiolaria varicosa. Smith, Report on "Alert" Collections, p. 109, pi. vii. tigs. M, M'.
Modiola strigata, (Young) Reeve, Conch. Icon., vol. x. pi. xi. fig. 83.

Habitat. — Port Jackson, Sydney, 2 to 10 fathoms.

This species has not, I believe, been as yet noticed from any other than the Sydney
district.

Modiolaria cuneata, Gould (PI. XVI. figs. 7~7a).

Modiolaria cuneata, Gould, Proc. Boston Soc. Nat. Hist., 1861, vol. viii. p. 38 ; Otia Conch.,
p. 176.

Habitat. — Port Jackson, Sydney, in 6 to 15 fathoms (Challenger); False Bay, Cape
of Good Hope (Gould).

REPORT O.N THE LAMELLIBRANCHIATA. 279

This species is not quite so elongate as the European JSIodioJaria marmorata of
Forbes, but corresponds in other respects, so that it is questionable whether it should not
take varietal rather than specific rank.

Another species described bj^ Fischer under this name (Jouni. de Conch., vol. xxx.
p. 53) may be called Modiolaria Jischeri. It was dredged in the Bay of Biscay, at a
depth of 1160 metres.

Modiolaria semigranata (Reeve).

Liiliodoinus seiidgranatus. Reeve, January 1858, Conch, loon., vol. x. pi. v. figs. 28, a, h.
Modiola suhclavata, Libassi, Atti Accad. Sci. Palermo, 1859, vol. iii. p. 13, fig. 7.

Habitat. — Station 70, w-est of the Azores, in 1675 fathoms (Challenger); Lanzerote
and Tenerife (M' Andrew).

None of the specimens from this locality are as large as the fossil shells figured by
Libassi. In the living state they are more or less covered with a yellowish epidermis,
which is of a hirsute character on the posterior portion of the valves. They varj' con-
siderably in form, some being longer and narrower than others ; all, however, exhibit the
median sinuation at the ventral margin. The largest of them is only 5^ mm. in length,
but a specimen from Lanzerote presented to the Briti.sh Museum by the late R. M' Andrew,
Esq., exceeds that by 2 mm.

Modiolarca, Gray.

Modiolarca trapezina (Lamarck).

Modiola trapesina, Lamarck, Anira. sans vert., ed. 2, vol. vii. p. 24.

Modiola trapezina, Kiister, Conch. Cab., vol. viii. Heft. iii. pi. vi. figs. 16, 17.

Modiolarca trapezina, Gray, Synopsis Brit. Mus., 1840, p. 151; Proc. Zool. Soc. Lond., 1847,

p. 199.
Modiolarca trapezina, H. and A. Adams, Gen. Rec. Moll., vol. iii. pi. cxxii. 6gs. 1, \a.
Modiolarca trapezina, Cheuu, Man. de Conch., vol. ii. p. 156, fig. 777.
Pliaseolicama trapezina, Hup6, Gay's Hist. Chile, Malacologia, pi. viii. fig. 9.
Pliaseolicuma magellunica, Eousseau, Voy. au Pol. Sud. Moll., p. 116, pi. xxvi. figs. 2, a-d.
Gaimardia trapesina, Gould, Wilkes's United States Explor. £.\ped., pi. xli. fig. 568.

Habitat. — Station 311; ofi" the coast of Patagonia, in 245 fathoms, a single dead
valve only. Station 315, off the east side of the Falkland Islands, Hving at a depth of
12 fathoms; also dead shells at Marion Island, south-east of the Cape of Good Hope,
in 50 to 100 fathoms; and finally in Royal Sound, Kerguelen Island, "on the surface,"
no doubt attached to floating Algxe, and also dead, in 28 fathoms.

The form of this species is somewhat variable, especially with regard to the anterior
end, some specimens (t'lVZe Gould's figure) having this part considerably narrower and
more prolonged than others. The hinge is generall)' composed of a single small

•280 THE VOYAGE OF H.M.S. CHALLENGER.

tubercular tooth in each valve, and I have never met with any specimen having douljle
this number as is stated to be the case by JNIessrs. Adams and Chenu. Sometimes these
tubercles may be wanting in one or even in both valves, the latter being apparently a
rare occurrence.

Modiolarca kerguelensis, n. sp. (PL XVI. figs. 8-8a).

Testa fragilis, alba, aliquanto iridesceus, incrementi lineis striata, elongata antice
angustata, jjostice altior, curvatim oblique truncata, mediocriter convexa. Margo dorsi
posticus perelongatus, fere rectilinearis, rotund o-angulatim cum latere postico junctus.
Margo ventris antice indistincte subsinuatus, post medium late curvatus leviterque
adscendens, acute rotundatim in lateralem ambiens. Latus anticum brevissimum, sub-
acutum, posticum longissimum, latum. Umbones mediocriter prominentes, ad apicem
obtusi, circiter in I longitudiuis positi. Pagina interna paulo nitida. Cicatrix antica
prsecipua, subprofuuda, elongata, postica indistincta. Dentes duo cardinales in utraque
valva, anterioribus majoribus. Ligamentum internum elongatum, angustum, ligamento
externo perelongato, marginali.

This species is oblong, trapezoidal, Ijroader behind than in front, xevy thin, white, a
little glossy and iridescent, and sculptured with very fine concentric lines of growth.
The valves are moderately convex, verj' inequilateral, the umbones, which are small,
only a little prominent, and terminate in an obtuse smooth gloss}^ boss, being situated far
in front, at about one-sixth of the whole length from the anterior extremity. The
anterior dorsal margin is short, nearly straight, and very oblique, forming, with the up-
curving lower margin, a sharply rounded (almost beaked) end. The hinder margin is long,
subrectilinear, and directed slightly upwards. The ventral outline is broadly arcuate, with
a slight incurvation or sinus, a trifle in front of the centre. The posterior end is faintly
arcuate, oblique, and joins the upper and lower margins -with rounded angles. The
hinge-plate is very slender, and furnished with two unequal teeth in each valve, of which
the anterior ones are larger than the posterior, that in the left valve being shaped like an
inverted letter V, thus A. Behind the teeth there is a distinct elongate groove for the
reception of the internal ligament. The external ligament is very long, extending from
n front of the umbones nearly the whole length of the dorsal margin, to which it is
attached. The interior of the valves is white and a little glossy. The anterior muscular
impression is rather deep, and defined on the posterior side by a straightish thickened
edge, and above this there are indications of a second smaller scar. The posterior
cicatrix and the pallial line are very indistinct.

Length 13 mm., height 8, diameter 5^.

Habitat. — Off Royal Sound, Kerguelen Island, in 25 fathoms.

REPORT ON THE LAMELLIBRANCHIATA. 281

This species is remarkable for the iridescent gloss of the exterior, its elougato fonn,
well-developed hiuge-tceth, and the distinct internal ligament.

Myrina, H. and A. Adams.

Myrina coppingeri, u. sp. (PI. XVI. figs. 9-9Z>).

Testa oblonga, antice augustata, valde insequilateralis, epidermide viridi-flavescente
induta, concentrice tenuiter striata. Margo dorsi posticus elongatus, rectus, paulo sursum
inclinatus, ventralis rectiusculus, vel in medio vix sinuatus. Linea cardinalis crassiuscula,
transvcrsim striata, in medio ligamento fere omnino interno interrupta. Pagina interna
ceeruleo-albida, iridescens.

This species is oblong, convex, about twice as long as high, considerably narrower at
the anterior end than behind. It is moderately strong, covered with a greenish-yellow
epidermis, and finely concentrically striated. The posterior dorsal margin gradually
ascends from the umbones, and is rectilinear, the ventral outline being also straightish,
but very slightly incurved at the middle. The umbones incline over towards the front,
and are situated at about one-sixth of the entire length from the anterior extremity.
The hiuge-liue is rather strong, striated across at both ends, and interrupted at the
middle by the brown ligament, which is internal and scarcely at all visible externally.
The interior is bluish-white, a little glossy and iridescent.

Length 9 mm., height 4f, diameter 3|.

Habitat. — Station 184, east of Cape York, North Australia, in 1400 fathoms ;
Globio-erina ooze.

This differs from the only known species of the genus in having the hinge-line finely
striated across on each side the ligament. Idas of Jeffreys has the hinge-plate similarly
crenated, but the ligament is described as external.

Idas, Jefi"reys.

Idas dalli, n. sp. (PI. XVI. figs. 10-10&).

Testa elongata, obliqua, parva, pellucida, nitida, iusigniter inaequilateralis, tenuissima,
modioliformis. Linea cardinalis bre^'is, recta ; latera obliqua, posticum leviter arcuatum,
anticum longius, in medio incurvatum. L^mbones parvi, acuti, parum prominentes, ante
medium linea; cardinalis denticulata) coUocati.

This little species is very narrow and elongate, thin, semitransparent, white, glossy,
almost destitute of sculpture, exhibiting only traces of fine lines of growth. It is oblique
in regard to the straight hinge-margin, the hinder side being slightly excurved, and the
anterior a little sinuate at the middle, the sinus marking a faint depression which
radiates from the umbones down both valves. The beaks are small, a little prominent

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 36

282 THE VOYAGE OF H.M.S. CHALLENGER.

beyond the dorsal line, and situated rather in front of the centre of it. The hinge-line is
slender and finely dentate nearl}' from end to end, some of the denticles near the middle
being the smallest, and a few at the posterior extremity the largest. The interior is
glossy, but hardly jjcarly, the muscular scars Ijeing indistinct.

Length 5^ mm., height 2^, diameter 2.

Hahitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

This curious species is not " nacreous " like the type of the genus Idas, and of a very
different form. I cannot discover in any of the odd valves (no complete specimen was
obtained) any trace either of an internal or external ligament. It is, I expect, of a very
slight character, and marginal.

. ' Dacrt/diam, Torell.

Dcccrydiiim vitreum (MciUer).

MoiUola (?) vitrea, MiJller, Ind. !iroll. Gronl., p. 19.

Dacrijdium vitreurn, Torell, Spitzbergens Molluskeufauna, p. 138, pi. L tigs. 2, a, h.

Dacrydiuin vitreurn, Jeffreys, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 429.

Dacrydium vitreurn, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 569.

Dacrydium vitreurn, Sars, Moll. Eeg. Arct. Norv., p. 28, pi. iii. figs. 2, a, h.

Hahitat. — Stations 73 and 78, west and east of the Azores, in 1000 fathoms.

For the synonymy and distribution of this species reference .should be made to the
above quoted j)apers by the late Dr. Gwyn Jeffreys.

Dacrydium occidental e, n. sp. (PI. XVII. figs. 1-la).

Testa Dacrydio vitreo similis, sed magis quadrata, margine inferiori magis incur-
vato, dorsali minus convexo.

This species resembles Dacrydium vitreurn in colour, texture, sculpture, and hinge,
but appears to be constant in its difference of form. It is not quite so convex, has a less
peaked anterior end and a more oblong-squarish appearance, the margin Ijehind the
umbones being less sloping backwards, the arcuation at the middle less prominent, and
the ventral outline more concave.

Length 4^ mm., height 2f, diameter if.

Hahitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

Hacrydium meridionalis, n. sp. (PI. XYII. figs. 2-2o).

Testa tenuis, alba, ixregulariter subpyriformis, mediocriter inflata, liris tenuibus con-
centricis aliisque paucis radiantibus cancellata, striis incremeuti sculjjta. Umbones parvi,
ad apicem obtusi, peculiariter clypeati. Margo cardinalis mediocriter elongatus, rectus,
inferior late rotundatus. Latus anticum leviter incurvatum, posticum excurvatum.

REPORT ON THE LAMELLIBRANCHIATA. 283

Linea cardiuLs mediocriter lata, iu medio sulco ligamenti clongato arata, utrinquo trans-
versim minute striata. Pagiua intci'iia uitida, microsco])ice subpunctata, marginc pcstico
cremiliitd.

This species has the form of certain Modluhn, the anterior side being produced
upwards so that the beaks are not apical. It is thin, white, somewhat glossy, moderately
tumid, and irregularly pear-shaped. The anterior side is slightly incurved where the
byssus would pass between the valves. The hinder margin is broadly excurved and the
lower outline well rounded. The umbones are small, terminate in a remarkable, obtuse
shield defined by a raised edge or collar. They incline towards the front, and arc much
nearer that end of the hinge-plate than the posterior. This is rather broad, bears a con-
spicuous long ligamental groove commencing in front under the beak and extending
backwards in a slightly oblique direction, and both in advance of the furrow and behind
it is finely striated across. The interior of the valves is glossy, minutely subpunctate,
and has the posterior margin armed with a few denticles. The exterior sculpture consists
of fine lines of growth, coarser concentric lirse, and radiating ridges, which appear to vary
in number in difi"erent specimens.

Length 4i mm., height 6, diameter 3.

Habitat. — Prince Edward and Marion Islands, in 100 to 150 fathoms (about 1200
miles south-east of the Cape of Good Hope).

This species probably attains larger dimensions than those given al)ove. It differs
from the typical species of the genus {Dacrydium vitreum) in having the hinge-plate
striated across in front of, as well as behind the beaks, in the character of the ligamental
furrow, and in the tips of tlie um1)ones.

Family P i x N i D ^.
Pinna, Linne.
Pinna tasmamca, Tenisou- Woods (?).

Pinna tasmamca, Tenison- Woods, Proc. Roy. Soc. Tasniau., l^'ri, p. 161.
Habitat.— Citation 1G2, off east Moncoeur Island, Bass Strait, in 38 fathoms; sand
and shells.

The single specimen from this Station accords very faii-ly with Mr. Teuison-Woods
brief diagnosis ; but, where so much depends on form in the determination of species, it
is almost impossible to identify with certainty without a good illustration or reference to
the figure of a closely allied form. The specimen at hand is very like Eeeve's figure of
Pinna, carolinensis^ (^^ Pinna subviridis. Reeve), botli as regards outline and colour.
It differs, however, in having fewer ridges and much larger scales. There are five

1 Conch. Icon., vol. xi. \A. \\\\v. fig. 66.

284 THE VOYAGE OF H.M.S. CHALLENGER.

principal ribs at rather equal distances, the first forming the straightish dorsal line. In
addition, towards the umbones, there is a slighter ridge in each space between the large
ribs which soon becomes obsolete. Also near the ventral margin there are four or five
obsolete ridges, which are chiefly indicated by that number of rows of moderately
distant small scales. The scales on the principal costse are very large, rather tubular and
elevated.

Family A v i c u l i d .-e.
Malleus, Lamarck.

Malleus alhus, Lamarck.

Malle^is alhus, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 91.
Malleus alhus. Reeve, Conch. Icon., vol. xi. pi. i. fig. 1.
Malleus alhus, Chenu, ilan. Conch., vol. ii. fig. 81.5.

Habitat. — Cape York, in 3 to 12 fathoms.

This well-known shell has been recorded from Japan, China, and Pliilippine Islands,
and probably has a still wdder distribution in eastern seas.

Avicula (Klein), Bruguiere.
A'vicula macro2')tera, Lamarck.

Avicula macroptera, Lamarck, Anim. sans vert., ed. 2, vol. \n. p. 97.
Avicula macroptera. Reeve, Conch. Icon., vol. x. pi. iL fig. 2.
Avicula macroptera, Dunker, Conch.-Cab., ed. 2, p. 22, pL vii.

Habitat. — Station 186, off" Cape York, North Australia, in 8 fathoms; coral mud.
This large species is also said to have been obtained at the Moluccas.
Avicula {3Ieleagrina) muricata, Reeve.

Avicula muricata. Reeve, Conch. Icon., vol. x. \>\. vi. fig. 12.

Avicula {Mcleagrina) muricata, Dunker, Conch.-Cab., ed. 2, p. 47, pi. xvi. fig. 2.

Habitat. — Station 187, near Cape York, North Australia, in 6 fathoms ; coral mud.

All the Challenger specimens of this species are young shells. Reeve's figure was
taken from a specimen which was to some extent Ijroken on the posterior side, so that
the sinus at the upper part appears too deep. A feature worth remarking is the fine
radiate ridges on the anterior auricle.

Avicula {Meleagrinct) sqiiamidosa, Lamarck.

Avicula squamulosa, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 100.

Avicula squamulosa, d'Orbiguy, Voy. dans TAmor. Mdrid., p. 658.

Avicula squamulosa, d'Orbigny, in Sagra's Hist. Cuba, Mollusques, vol. ii. p. 342.

Habitat. — Station 36, off" Bermuda, in 30 fathoms ; coral.

REPORT ON THE LAM ELLIBRANCHIATA. 285

This species, which was originally described from Braziliuu specimens, will, I believe,
include several others from the Caribljean Sea, namely, Avicula Jlahellum, Eeeve,
Avicula chamoides, of the same author, and apparently the young of the preceding,
Avicula hovrida of Dunker, Avicida cda-perdicis of Eeeve, and possibly one or two
more.

Avicula [Meleagrina) smaragdina, Eeeve.

Avicula smaragih'na, Reeve, Concli. Icon., vol. x. pi. xii. fig. 4.5.
Avicula smaragdina, Smith, Eeport "Alert" Coll., p. 113.

Habitat. — Off Cape York, in 3 to 12 fathoms.

This species w^as collected by Dr. Coppinger of H.M.S. "Alert" on the coast of North-
east Queensland, and was presumed by Eeeve to have come from the Moluccas.

Perna, Bruguiere.
Perna samoensis, Baird.

Pcrna (Isof/iwmon) samoeiii<ii<, LairJ, in Urenchley's Cruise of the "Curajoa," p. 454, pi. xlii. fig. 8.

Habitat. — On the reefs at Samboangan, Philippine Islands, in 10 fathoms; also on the
reefs at Honolulu, Sandwich Islands.

This species was descriljed from specimens collected ai Tutuila, one of the Samoa
Islands, and other examples of it from the Keeling Islands in the Indian Ocean are in the
collection of the British Museum. It is readily recognised by the radiating brown lines
which run l^etu-ecn and not upon the slightly raised ridges as stated by Baird. These
lines, which cannot be called purple, exist only on the convex valve. The form of this
shell is very variable, some of the Keeling specimens being extraordinaril}- produced into
a wing-like projection behind.

Perna vitrea, Eeeve.

Perna vitrea, Reeve, Conch. Icon., vol. xi. pi. ii. fig. 10.

Habitat. — Hilo, Sandwich Islands.

Eeeve gives the Eed Sea as the locality of this species, but I should state that the
specimens in Cuming's collection are marked with the locality " Sandwich Islands.'"' The
description of the colour of this shell in the Conchologia Iconica {" of a shining, dark,
chestnut-red colour") does not well apply either to the types or the Challenger specimens.
The figure, however, is more correct in this respect, the pale zones being, however, a little
exaggerated. At a more mature age than the shell depicted, the posterior end becomes
somewhat wini:red.

286 THE VOYAGE OF H.M.S. CHALLENGEK.

Famil}^ S P o N D Y i, i d .e.

Sjyonch/lus, Liiine.

Spondylus zonalis, Lamai'ck.

SponJijlns zonalls, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 191.

Spondijlns mncilis, Chenii, lU. Con., p. 5, pi. vii. figs. 3, -1.

Spondyhis zonalis, Martens, Moll. Mauritius, &c., p. 313.

Spondylus zonalis, Eeeve, Conch. Icon., vol. ix. pi. viii. figs. 29, a, U.

Spondylus zonalis, Sowerby, Thes. Conch., vol. i. p. 429, ligs. 12, 18, 27, GO.

Spondylus lierinaceus, Chenu, op. cif., p. 6, pi. xsv. figs. 3, 4.

Habitat. — Station 186, off Cape York, in 8 fathoms; coral mini.

One of the two specimens from this locality agrees very fairly with the variety
figured by Eeeve (fig. 296). The other has the itpper or free valve white, with the
exception of a few dark spots to'W'ards the umbones. Some of the spines near the outer
margin are tinted with fleshy orange, and the lower valve hiis more of the colour. The
interior is white, with a rich orange-red border, within which is a narrow zone of a pale
olive-brownish tint, becoming darker towards and upon the hinge-teeth. The margin in
the other example is not nearly so viAad, and of a lilac colour, and, Uke that of the other
shell, is zoned within with olive-brown. The species has been recorded from the
Mauritius and the Philippine Islands.

Spondylus victorice, Sowerby.

Spondylus victorice, Sowerby, Proc. Zool. Soc. Lond., 1859, p. 428, pi. .\lis. tig. 8.
Spondyhis victorice, Smith, Report "Alert" Coll., p. 114.

Yav. = Sjwndylus wrightianus, Crosse, Jouni. de Conch., 1872, vol. xx. p. 360, vol. xxi. p. 253,
pi. ix. figs. 1, \a.

Habitat. — Station 188, south of New CTuinea, in 28 fathoms; green mud.

The specimens from this locality belong to the var. lurightiana, having straight,
pointed spines. Eemarks on the distribution of this species will be found in the Report
on the " Alert " collections.

Flicatula, Lamarck.
Plicatida ramosa, Lamarck.

Plicatvla raiuosa, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 176.
Flicatula ramosa, Hanley, Recent Shells, p. 288.
Spondylus harhadensis, Petiver, Gazopbil., pi. xxiv. fig. 12.

Habitat. — Station 322, off the mouth of the Rio de la Plata, in 21 fathoms; sand

and shells.

The shells from this locality, which I associate with this West Indian species, are
usually pyriform, and rather compressed, the free valves being almost flat, and invariably

EEPORT ON THE LAMELLIBRANCHIATA. 287

shalluwer tlian the attached valves. The}' are more or less tinted with rt'ddish-ljrown
externally, and, with the exception of a naiTow pale brownish border, are uniformly white
within. The ])licEe are rather similar in most specimens, not very large, and sometimes
interrupted towards the apex. The attaehed \'alves may be almost entirely or but very
little adherent.

Plica tida sp.

Habitat. — Amboina, 15 to 20 fathoms; and Flinders Passage, North Australia, iu
7 fathoms.

A single valve from each of these localities probably belongs to Flicatula imhricata,
as identified by Sowerby in his monographs in the Thesaurus Conchyliorum and the
Conchologia Iconica, but on accoimt of the bad condition of the one, and the
immaturity of the other, I cannot affirm so definitely.

Family L i M i D .i;.

Lima, Bruguiere.
Lima squamosa, Lamarck (juv.).

Lima squamosa, Lamarck, Anim. sans vert., oil. 2, vol. vii. p. 115.
Lima squamosa, Lischke, Japan, Meeres-Concb., Tlieil. i. p. 162.

Hahitat. — Off Tenerife, in 70 fathoms; and Station 212, south of Mindanao, Philip-
pine Islands, in 10 fathoms.

Only a single minute valve was obtained of this well-known species off Tenerife, and
a small perfect specimen at the Philippines. Its distribution is fuUy discussed by Lischke
in the above-named work. The British Museum collection contains specimens from the
Red Sea, Ceylon, Philippine Islands, Darnley Island, the Louisiade Archipelago, and New
Zealand. After a careful examination and comparison of these specimens with Mediter-
ranean examples, I have failed to discover any constant specific differences. The shells
may, as a rule, appear rather broader and the ribs a little stouter ; but other intermediate
forms occur, so that it seems impossible to draw a line of separation. The Lima pavci-
costata of the Conchologia Iconica, w^hich mav be different from that of the Thesaurus
Conchyliorum, I also consider a variety of this species.

Lima lata, n. sp. (PI. XXIV. figs. 3-3a).

Testa subcompressa, fere clausa, insequilateralis, obliqua, lata, antice oblique truncata,
profunde excavata, postice primo prope marginem dorsalem leviter incurvata, deinde late
arcuata, inferne semicirculariter curvata. Valvie mediocriter crassse, albse, costis radian-

288 THE VOYAGE OF H.M.S. CHALLENGER.

tibus circiter 36, plus miuusvc spinulis brcvibus subacutis cavis ornatis, iustructa.
Interstitia costis angustiora, medioeriter profunda, transversim rugose striata. Area
dorsalis profunde cxcavata, cuneiformis, fossa ligameutali triangulari sculpta. Pagina
interna nitida, hand profunde radiatim sulcata.

Length 36 mm., height 42, diameter 15.3.

Habitat. — Station 109, off St. Paul's Rocks in the Atlantic, north-east of Brazil, in
104 fathoms ; and Station 201, off the west side of Mindanao, Philippine Islands, in
82 fathoms.

This fine species is very like Lima squamosa, but is l)roader and has more numerous,
finer, and more sharpl}^ spined ribs. The anterior straight slope is shorter, the peculiar,
triangular ligament-pit is quite different, and the angle formed at the umbones by the
dorsal and anterior margins is less acute.

In reckoning the number of ribs as thirty-six, it should be observed that the very fine
ones on the front excavation are not included. The anterior auricles are almost obsolete,
and indeed invisible when the valves are regarded sideways, being hidden within the
concavity. The hollow spines on the costse are rather pointed, long, and a little curved.
The interior of the valves is glossy, and, with the exception of the upper portion, which
is thickened witli a shelly deposit, is shallowly grooved and ridged, the grooves corre-
sponding to the external ribs.

The few specimens from the Philippines are all of small size, the largest being only a
third the length of the unique shell from the Atlantic. After a very careful study of
them I cannot discover any grounds for their separation, the form being the same, the
ligament of a similar shape, and the costse only two or three fewer. It therefore appears
that this species, like Lima squamosa, occurs in very remote localities.

Lima multicostata, Sowerby ( = Lima carihtea, d'Orbigny), has about the same number
of ribs as this species, but is of' the same form as Lima squamosa.

The differences which distinguish these three forms are but very slight, and it is not
improbable that all belong to one and the same species, and it is curious to note that
each of them occurs both in the Atlantic and Pacific. Other closely allied species are
Lima tetrica, Gould, from the Gulf of California, Lima huUifera, Deshayes, from
Reunion, and Lima zealandica, Sowerby, from New Zealand.

Lima multicostata, Sowerby.

Lima multicostata, Sowerby, Thes. Conch., vol. i. p. 85, pi xxii. fig. 38.
Lima multicostata, Sowerby, Conch. Icon., vol xviii. pi. i. fig. 4.

Lima carihcm, d'Orbigny, Sagra's Hist. Cuba, MoHusques, vol. ii. [i. 3.37 ; Atlas, pi. xxviii.
figs. 17-19.

Habitat. — Port Jackson, New South Wales, in 2 to 18 fathoms ; and Station 172, oft'
Tongatabu, in 18 fathoms; also Station 56, off Bermuda, in 1075 fathouLS.

REPORT ON THE LAMELLIBRANCHIATA. 289

This species, whicli T cannot separate from Liiaa caflhaa, is said to be Mediterranean
by Mr. Sowerby, and he is probably correct. In the British Museum there are specimeu.s
from Port Stephens, Eaine Island, Torres Strait, and Kangaroo Island, \vhi(;h ai)pear to
be absolutely identical in every respect. It resembles Lima squamosa in form, but ha.s
many more and finer ribs, whicli have more delicate prickles n})nn tlicm.

Lima tahitensis, n. .sp. (PI. XXIV. figs. 4-4a).

Testa brevis, oblicjue subqnadrata, compressa, ingequilateralis, all)a, antice excavata,
costis ad quindecira spinis erectis cavis elongatis pulcherrime ornatis instructa, in
interstitiis liris concentricis prsecipuc umbones versus fortibus cancellata. Auriculre
valde insequales, anticaj fere obsoletiie. Area dorsalis angusta, parva, excavata. Pagina
interna nitida, radiatim sulcata.

Length 9 mm., height 10, diameter 4^. . "

Habitat. — Tahiti, in 30 to 40 fathoms.

This charming little shell differs from Lima squamosa in its shorter and squarer
form, fewer ribs, more erect and longer spines, and the coai'ser liras between the costa;,
especially near the umbones, where they give quite a cancellated appearance to the valves.
The anterior slope is a little concave, and ornamented with a few minutely prickled
lirse.

Lima angulata, Sowerby.

Lima angulata, Sowerby, Thesaurus, vol. i. p. 86, pi. xxii. figs. 39, 40.

Lima angulata, Sowerby, Concb. Icou., vol. xviii. pi. iii. fig. 1 3.

Lima hasilanica, Adams and Reeve, Voy. "Samarang," p. 75, pi. xxi. fig. G.

Lima orientalis, Adams and Reeve, op. cit., p. 7.5, pi. xxi. fig. 7.

Radula {Munti'Unm) angulata, Angas, Proc. Zool. Soc. Lond., 1865, [i. 056.

Radula {Mantellum} orieritahs, Angas, oji. cit., 1871, p. 101.

Habitat. — Port Jackson, New South Wales, in 2 to 7 fathoms (Challenger) ; Panama
and Bay of Carracas, in 10 to 12 fathoms (Sowerby) ; Philippine Islands (Adams and
Reeve) ; Port Lincoln (Angas).

I do not see any sufficient reasons for separating the above-named forms, and 1
believe that the Lima fasciata of Sowerby {nee Linn.) is probably also merely a large and
rather coarsely sculptured variety of this species. The outline is very like in all
of them.

(zool. CHALL. EXP. PART XXXV. 188.''i.) Mm 37

1>90 THE VOYAGE OF H.M.S. CHALLENGER.

Lima goh'ath, Soworby.

Lima ijuliaih, Sowerby, Proc. Zool. (Soc. Lond., 1883, p. 30, pi. vii. ti^. 3.
Lima (xcavnta, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. TiQi.

IlahitiU. — Station 23G, off south of Japuu, in 775 fathoms; and Station 311, off the
west coast of Southern Patagonia, in 245 fathoms.

A single crushed specimen, about 2 inches in length, from the former locality, and a
rather smaller odd valve from the latter, are all that were obtained. Whether this species
1)6 really distinct or not from the Norwegian Lima excavata of Fabricius I cannot decide,
but Mr. Sowerby, who has a very accurate appreciation of differences, is of opinion that
it is different. The Challenger valves are almost smooth down the middle, and the
lateral strise are finely punctate, whilst Norwegian examples are striated at the centre,
and the lateral sulci are not punctured in the same manner.

It is very curious that Japan and South Patagonia should furnish apparently the
same species.

Lima (Ctenoides) tenera, Chemnitz.

Livia tenera, CLiemnitz, Conch. -Cab., vol. vii. p. 3.34, pi. Ixviii. fig. G53.

Lima tenera, Sowerby, Thes. Conch., vol. i. pi. x.xi. figs. 2, 3, 10, 11.

Lima tenera, Sowerby, Conch. Icon., vol. xviii. pi. ii. fig. 7.

Lima tenerra, Hanley, Cat. Eeeent Shells, p. 266.

Lima (Ctciioidea) tenera, Martens, Moll. Maskaren, p. 315.

Habitat. — Levuka, Fiji Islands, in 12 fathoms (Challenger).

This species is very like the West Indian Lima scahra, but is more finely sculptured.
Both are equally variable in form. In the British Museum there are specimens from the
Island of Narai, Fijis, collected at low water by Macgillivray, from Sir C. Hardy's Island
(Jukes), and from Port Essington. Other localities are Zanzibar (Mus. Cuming) ;
Bourbon, Reunion, and Mauritius (Martens) ; Philippine Islands and Singapore
(Sowerby).

Lima {Manfellvm) hians, Grmelin.

Lima hians, Gmelin, Syst. I>Iat., p. 3332.
. LAma hians, Forbes and Hanley, Brit. Moll., vol. ii. p. 268, pi. Hi. figs. 3-5.
Lima hians, Jefireys, Brit. Conch., vol. ii. p. 87, vol. v. p. 170, pi. xxv. fig. 5.
IJma hians, Jefireys, Proc. Zool. Soc. Lond., 1879, p. 564.

Habitat. — Station 36, off Bermuda, in 30 fathoms ; coral.

The recent and fossil distribution of this species has been given by Jeffreys, but he
has not recorded it from the West Atlantic region.

REPORT ON THE LAMELLIBRANCHIATA. 291

Lima (Mantellum) loscombii, Sowerby.

Lima loscombii, Sowerby, Genera Rec. and Fds. Shells, fig. 4.
Lima loscombii, Forbes and Hanley, Brit. Moll., vol. ii. p. 2iJ5, i>l. liii. figs. l-.'5.
Lima loscombii, Jeffrey.?, Brit. Coneli., vol. ii. p. 85, vol. v. jil. xxv. fig. 4.
Lima loscombii, Jeffreys, Proc. Zool. Soc. Lend., 1879, p. 564.

Habitat. — Station 75, off the Azores, in 450 fatlioms, and oft' Nightiugah^ I.slauil,
Tristan da Cunha, in 100 to 150 fathoms.

The distribution of this species, both recent and fossil, has ah'cady been given by
Jeffreys, Weinkauff, and others, but it has not, I believe, been previously recorded from
so southern a locality as Tristan da Cunha.

Lima (Limatula) torresiana, n. sp. (PI. XXIV. figs. 5-5").

Testa perconvexa, sequilateralis, subovata, solidiuscula, costis radiantil)us subnodu-
losis 22-24 lirisque tenuibus confertis concentricis cancellata. Intcrstitia sul)profuiida.
costis angustiora, in medio lira filiforme sfepe bipartita. Umbones promincntes, involuti.
Area cardinalis elliptica, fossa ligamenti profunda sculpta. Pagina interna radintini
sulcata, margine exteruo fortiter dentato circumdiitii.

This is a rather solid species, equilateral, very convex, somewhat ovate, and sculptured
with about twenty-four radiating riblets, which are prettily nodulose, the nodules being
compressed and very close together. The intervening sulci are somewhat narrower than
the costse, frequently have a very slender thread-like lira up the middle, and are crossed
by fine, closely packed, concentric lirse, which connect the nodules on the ribs, or in
other words they are continuous and somewhat thickened on crossing the ribs. The
umbones are fairly prominent, and well incurved at the tip. The hinge-area is of an
elongate elliptical form, and exhibits a rather sunken central diamond-shaped ligament-
pit. The interior is regularly grooved, the sulci corresponding to the extei-nnl eosta^,
and the outer margin is coarsely and bluntly dentate.

Length 8 mm., height 10, diameter 7i.

Habitat. — Station 18G, off Cape York, in 8 fathoms; conn mud.

This is a shorter and much more strongly sculptured shell than Lima bullata. It
also closely approaches Lima japonica, (A. Adams) Sowerby, but not the Lima japoniru
of Dunker, which is a very different species, and may hereafter be called Lima dKnh'vi,
as Sowerby's shell has priority of publication.

•292 TIIK VOYAGE OF H.M.S. CHALLENGER.

Lima {Limatida) pygmcBa, Philippi.

Lima pijffmmrt, Philippi, Wiegmanii's Aichiv f. Naturgfsch., 1845, p. 56.

Limatida falklandica, A. Adams, Proc. Zool. Soc. Lond., 1863, p. 509.

Radula {Limatula) pygmma, Smith, Phil. Trans. Eoy. Soc, 1879, vol. clxviii. ji. 191.

Habitat. — Eoyal Sound and Balfour Bay, Kerguelen Island, in 28 to (jO fathoms;
also Prince Edward and Marion Islands, in 50 to 150 fathoms.

This species also occurs in the South Patagonian region.

Lima [Limatida) hidlata (Born).

Ostrea hullata, Born, Mus. Caes. Vindobon, p. 110, pi. vi. fig. 8.

Pecten hidlatus, Chemnitz, Conch. -Cab., vol. vii. pp. 267 and 348, pi. l.wiii. tig. 649i'/.

Odrea inflfifa, Gmelin, Syst. Nat., p. 3321.

Lima bidlafa, Sowerby, Thes. Conch., vol. i. p. 84, pi. xx. figs. 32, 33.

Lima Indlaia, Sowerby, Conch. Icon., vol. xviii. pi. i. figs. 3, «, h.

Lima strani/ei (A. Adams MSS.), Sowerby, Conch. Icon., pi. iii. fig. 15.

Habitat.- — Port Jackson, New South Wales, in 2 to 10 fathoms; and Station 162, off
East Moncoeur Island, Bass Strait, in 38 fathoms (Challenger) ; Port Stephens (Jukes, in
Brit. Mus.) ; Moreton Bay (Mus. Cuming) ; Sorsogon, Philippines (Sowerby).

This species varies considei'ably in shape, some specimens being narrower than others.
I do not see any suiRcient reason for separating the form named Lima strangei, the
slight obliquity noticed by Sowerby being unimportant.

Lima (Limatida) subovata, Jeffreys.

Lima subovata, .JeiTreys, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 427.
Lima subovata, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 563, pL xlv. fig. 2.

Habitat. — Station 78, off the Azores, in 1000 fathoms.

For the distribution of this species see the above papers, in which the Challenger
specimens have already been referred to.

Lima (Limatida) confusa, n. sp. (PI. XXIV. figs. 6-6a).

Lima ovata, Jeifreys {nee Searles Wood), Ann. and Mag. Nat. Hist., 1876, vol xviii. p. 426.

Testa parva, tenuis, ovata, convexa, nitida, subpellucida, liris gracillimis radiantibus
ad 29 instructa, striisque incrementi tenuissimis sculpta. Margines laterales per lirarum
extremitates leviter serrati. Umbones prominentes, paulo incurvati.

Length 2^ mm., height 3f, diameter 2\.

Habitat. — Station 78, off the Azores, in 1000 fathoms; Station 120, off Pernambueo,
Brazil, in 675 fathoms ; and Station 23, off Sombrero Island, West Indies, in 450
fathoms (Challenger); North Atlantic (Station 12), in 1450 fathoms ("Valorous").

KEPORT ON THE LAMELLIBRANCHIATA. 293

I cannot agree with the hitc Di-. Gwyu JeftVeys in considering this species the same
as the Crag fossil Lima ocata of Searles Wood. That is a differently shaped shell, more
strongly ribbed down the middle of tlie valves, entirely or almost wholly destitute of
lirfe at the sides where the margins are even ami not serrate, and strongly dentate
within the ventral outline. Jeffreys gives the number of ribs at " about 50." Should
this be 30 ? For in two valves received by the British Museum from liini from the
" Valorous " expedition I find that number.

Lima (Limatula) sp.

Habitat. — Station 104, Mid Atlantic, south-west of SieiTa Leone, in 2500 fathoms.

A single specimen, which is too damaged for description, apparently belongs to a new
species. It is of small size (5 mm. high), of an elongate, narrow form, excessively
thin, glossy, and sculptured with numerous very fine hair-like radiating lirse, which
produce dentate margins to the valves, and rather conspicuous lines of growth, giving
the surface a more or less cancellated appearance.

Lima {Limatula) sp.

Habitat. — Station 317, north of tlie Falkland Islands, in 1035 fathoms.

The single sliell obtained at this Station may be a more mature example of the species
from Station 104. It is thicker in texture, more strongly lirate, and not so pointed
beneath. It also closely approaches Lima subovata, but is ornamented with a coarser
(!ancellation, has less prominent umbones, and is more rounded at the A^entral margin.

Lima (Limatula) s]).

Habitat. — Off Nightingale Island, Tristan da Cunha, in 100 to 150 fathoms.

A single minute valve from this locality approaches very closely Lima subovata, but
may be distinct. It is not quite so convex, not so pointed beneath, and has rather fewer
radiating lirae. The interior exhibits three thread-like lirse down the centre, with grooves
between them which terminate on the margin in little denticles. It may be the young
state of the species from Station 317.

Linm {Limatula.) laminifem, n. sp. (PI. XXIV. figs. 7-7a).

Testa parva, tenuis, pellucida, ovata, .superne truncata, secjuilateralis, mediocriter
eonvexa, laminis concentricis tenuibus numerosis, lirisque paucis obsoletis prope
medium instructa. Linea cardinalis gracilis, Isevis. Area ligamenti angusta, fossa

294 THE VOYAGE OF H.M.S. CHALLENGER.

mediana lata sculpta. Umbones centrales, ad apicem la3vigatum hand acuti, supra
marginem dorsalem vix producti. Pagina interna nitida, sculpturam externum exhibens.

Length 2 mm., height 3^, diameter 1^.

Habitat. — Station 23, off Sombrero Island, West Indies, in 450 fathoms ; Station 24,
off Culebra Island, in 390 fathoms.

This interesting little species is readily recognisable by the almost total absence of
radiating sculpture, and the very slender concentric lamellae. The radiating lirse which do
exist are very faint, and occur only down the central portion of the valves, giving the laminae
a somewhat frilled appearance. The auricles are equal and scarcely defined, the lateral
margins of the valves being regular and faintly curved at the upper part, and not constricted.

Lima sarsii is more distinctly radiately ribbed, is said to have the hinge-plate
"bluntly but distinctly crenulated across," and the front m;u'gin "strongly crenate and
notched within," features not occurring in the present species.

Family P E c T I N i D .E.
Pecten, Midler.
Pecten asperrimus, Lamarck.

Pecten aspernnms, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 14-5.

Pecten a-'^perriimis. Reeve, Conch. Icon., vol. viii. pi. xx. fig. 75.

Pecten asperrimus, Sowerby, Tlies. Conch., vol. i. p. 75, pL' xvii. fig. 156 (157 and l">iS?).

Juv. =Pec<e?j australis, Sowerby {non Pliilippi), op. eit., p. 76, pi. xix. figs. 219, 220.

Pecten australis, Reeve, loc. cit., pi. xxv. figs. 103, a, Ij.

Habitat. — Station 162, off East Moncoeur Island, Bass Strait, in 38 fathoms.

In the young state the rays of this species consist of a central ridge and two finer
lirae, one on each side, all very finely squamate as in Pecten australis. At maturit}' the
lirse usually number three on each side. Tlie closely allied Pecten prxtniim, Eecve, has
a broader central ridge to the rays, which in consequence look rounder, and the auricles
are larger. Like many other Pectens, this is also variable in colour, in some instances
being of a plum colour, in others orange or scarlet. The Challenger specimens are
uniformly reddish-orange.

Pecten patagonicus, King.

Pecten patagovicus. King, Zuol. .Joiun., vol. v. p. 337.

Pecten patagonicus, Sowerby, Thes. Conch., vol. i. p. 54, pi. xiii. fig. 16.

Pecten patagonicus. Reeve, Conch. Icon., vol. viii. pi. xxvi. fig. 110.

Pecten patagonicus, Smith, Proc. Zool. Soc. Lond., 1881, p. 44.

J\iv. = Pecten nifiradiafus. Reeve, op. cit., pi. xxxii. fig. 147.

1 = Pecten australis, Philippi, Wiegmann's Archiv f. Naturgesch., 1845, p. 56.

Habitat. — Station 312, South Patagonia, in 9 fathoms; and Station 315, Falk-
land Islands, in 12 fathoms.

KEPORT ON THE LAMELLIBRANCHIATA. 295

The right valve of this species is usually white or onl)' partly tinted with purplish-red,
and contrasts strongly with the red-rayed left valve. The specimen figured Ly Reeve is
rather abnormal in colour, as the ribs in most specimens are not alternately dark
and pale.

Pecten pusio (Linn^).

Ostrea pusio, Linn(5, Syst. Nat,., ed. 12, p. 1146.

Pecten ptisio, Forbes and Hanley, Brit. Moll., vol. ii. p. 278, pi. 1. figs. 4, 5, pi. li. fig. 7.

Pecten pusio, Jeffreys, Brit. Conch., vol. ii. p. 51.

Pecten pusio, Jeffreys, Proc. Zool. Soc. Lend., 1879, p. 557

Habitat. — Tenerife, Canary Islands, in 70 fathoms ; and Station 75, Azores, in
450 fathoms.

In this, as in other instances, I refrain from giving the copious synonymy and refer-
ences to a great number of works, a course only excusable in preparing a monograph.

Pecten sulcatns, Muller, A^ar.

Pecten sulcatus, Muller, 1776, Zool. Dan. Prodrom., p. 248, No. 2995.

Pecten sulcatus, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 557.

Ostrea arata, Gmeliu, Syst. Nat., p. .3327, No. 60.

Pecten aratus, Sars, Moll. Eeg. Arct. Norv., p. 17, pi. ii. tigs. Sa-S?*.

Pecten idams, Eeeve, Conch. Icon., vol. viii. pi. xxxiii. fig. 153. f

Habitat. — Station II., off' the coast of Portugal, in 470 fathoms; green mud.

The only specimen from this Station agrees with the variety crebricostata of Sars, in
which the riblets are very numerous and similar in both valves. The distribution of this
species, recent and fossil, having already been- given by Jeffreys, I have merely to call
attention to the identity of Pecten idceus, Reeve, a fact hitherto unnoticed.

Pecten gibbus (Linne).

Ostrea gibba, Linne, Syst. Nat., p. 1147.

Pecten gibbus, Lamarck, Anim. sans vert., ed. 2, vol. vii. p. 152.

Pecten gibbus, Sowerby, Thes. Conch., vul. i. p. 52, pi. .\ii. fig.=. 1, 2, and pi. xiv. fig. 72.

Pecten gibbus, Keeve, Conch. Icon., vol. viii. pi. ix. fig. 37, a-c.

Habitat.- — Station 75, off" the Azores, in 450 fathoms; volcanic mud.

Only one or two very small valves of this species were obtained. It is said to occur
on the west coast of Africa, and at the West Indies.

296 THE VOYAGE OF H.M.S. CHALLENGER.

Pecten noronhensis, n. sp. (PI. XXI. figs. 4-46).

Testa paulo inEequivalvis, couvexa, inaBquilateralis, alba, aurantio vel .saturato-rosco
maculata, costis ad 17 valde promineutibus instructa ; cost^e valvae dextrge iuterstitii.s
profundis pulcberrime transversim lamellatis latiores, laevigatse ; valva sinistra costis
paulo gracilioribus, interstitia sequantibus, lira mediana teiiui Ijipartitis instrur-ta, undique
et supra et inter costas tenuissime lamellata. Auriculae insequales, radiatim tenuiter
costulatro. Pagina interna imrpuraseens, alljo limbata, vel omnino alba.

This species is somewhat inequivalve, the right valve being a trifle deeper than the
left. It is rather convex, and inequilateral, and has an apparent obliquity, owing to the
hinder slope from the umboues being longer than the anterior. It is white, and more
or less copiously blotched with orange or deep rose. The valves are differently sculptured.
The right has the ribs (about seventeen in number) smooth above, and broader than the
deep intervening sulci, which are most beautifully ornamented with close and excessively
delicate concentric lamellae. In the left valve the ribs about equal the furrows in width,
are divided into two parts by a fine central lira, and are crossed by the very delicate lamellae
which also occur in the sulci. The ears are unequal. In the left valve both are concave
at the sides, especially the front one, which is the smaller. In the right valve the posterior
is incurved laterally, and the anterior is deeply cut in underneath and ornamented with
about five squamate ridges. The interior of the largest specimens is purple, with the
exception of a narrow white border, but smaller specimens are entirely colourless within.

Length 27 mm., height 26, diameter 12.

Habitat. — Station 113a, off Fernando Noronha, in 25 fathoms; volcanic sand and
gravel.

This species is considerably like Pecten gibbus, Linn., but may be recognised l)y the
following difi"erences. Judging from the few specimens at hand, it appears to be rather
more convex, more inequilateral, the ribs are stouter, fewer, more elevated and sharply
cut, and differently sculptured, and the posterior auricles are less oblique at the side and
more concave.

Pecten 2yhiH2)pii, Recluz.

Peden pJiilipjjii, Eecluz, Joiirn. de Conch., 1854, vol. iv. p. 52, pi. ii. figs. 15, IG.
Pecten philip2ni, Petit. Cat. Moll. Test. Europe, pp. 79, 200.
Peden pliiliiipn, Hidalgo, Moluscos Marin. Espaua, pi. xxxii. tig. 2.
Peden philippii, Weiukaiiff, Conchyl. Mittelm., vol. i. pp. 251, 300.
Peden commutatm, Monterosato, Poche Note Conch. Medit., 1875, p. G.

Habitat. — Station 75, off the Azores, in 450 fathoms; volcanic mud.

REPORT ON THE LAMELLIBRANCHIATA. '2\i7

This species appears to be distriljulud in some western parts of the; Metliterrancan,
on the coasts of Spain and Portugal, and at the Canary Islands, which is the most
southern locality at present known.

Monterosato changed the name of this species to Pccten commutatus, because
Michelotti had, previously to Recluz, designated a fossil form by the name Pecten
lAUippU. As that species belongs to Aimissium, a genus which is nowadays usually
recognised, it seems a pity to abolish the name by which the present species is so
well known.

Pecten limatuht, Reeve, var. (PI. XXI. figs. 5~5a).

Pecten limatula, Reeve, Conch. Icon., vol. viii. pi. xxviii. fig. 124.

Testa tenuis, paulo incequilateralis, interdum obliqua, fere ajquivalvis, mediocriter
convexa, pallida, radiis paucis zonisque concentricis dilutissime subroseis picta, superue
utrinque umbones roseo tincta. Valvse striis tenuissimis concentricis umbones versus
prsecipue conspicuis ornatse, costulisc^ue gracilibus circa quinquagenis minute squamulatis
instructse. Auriculae valde insequales (posticis majoribus radiatim costulatis, anticis
brevibus ad latera oblique truncatis). Postica valvse sinistrse inferne profunde sinuata,
ad extremitatem subtruncata. Uml)ones acuti, parvi, sublsevigati, marginibus lateralibus
concavis, postico in valva sinistra denticulate. Pagiua interna nitens, radiatim sulcata.

This is a thin, delicate shell, rather higher than long, of a somewhat oblique growth,
and consequently a little inequilateral. It is of a pale colour, but, being faintly rayed
and concentrically zoned with a very light rosy tint, has a general appearance of being
of that colour wdiich is heightened into a decided rose tint on both sides of the beaks.

The valves are only moderately convex, about equally deep, ornamented with about
fifty radiating riblets bearing innumerable minute erect scales. Some of the riblets do
not extend as far as the umbones, and being situated close to others, impart to them the
appearance of l)eing in pairs. Between the costellse the surface is adorned with
excessively fine concentric striae, which, however, towards the umbones, are replaced by
more distinct elevated lamellae, w'hich do not, however, cross the ridges, which at this
part are entirely destitute of scales. The beaks are rather acute, and somewhat glossy
near the tip, which consists of a very minute convex vitreous boss. The converging
sides, of which the posterior is armed with many minute cornpressed denticles, are rather
concave, unequal in length, the anterior being somewhat the longer, and form in the two
largest specimens an apical angle of about 100° and in some instances scarcely 90°.

The ears are very unequal. The anterior are short, obliquely truncate at the sides,
and radiately ribbed, the ribs being about seven in number, slightly squamous and verv
slender, with the exception of the upper marginal one, which is usually much stronger

(ZOOL. CHALL. EXP. PART XXXV. — 1885.) Mm 38

298 THE VOYAGE OF H.M.S. CHALLENGER.

tluiii the rest. The posterior auricle of the right valve is large, and has about ten fine
riblets, that of the left valve is deeply sinuated below, truncated at the end, and sculp-
tured with fine ridges (the marginal one being the largest) covered with closely packed
transverse squamulse. The portion of the sinus filled u]) during the growth of the shell
is white, somewhat concave, and crossed by coarse elevated lines of growth. The inner
surface of the valves is glossy, tinted like the exterior, and finely grooved and ridged ;
or, in other words, exhibits a reversal of the external ornamentation, the grooves
corresponding to the ridges of the exterior and the ridges to the intervening sulci.

Length 22i mm., height 24|, diameter 63.

Habitat. — Station 141, ofi'the Cape of Good Hope, in 98 fathoms; also Station 135,
ofi" Nightingale Island, Tristan da Cunha group, in 100 to 150 fathoms.

In the earliest stage this shell is smooth or only microscopically striated by lines of
growth. It then assumes a second style of ornamentation, consisting of fine wavy
radiating wrinkles which run in among the incipient cost8e. To this wrinkling succeeds
the fine concentric striae, which subsequently become more remote and less pronounced.

The Challenger shells above described do not correspond precisely with the single
type specimen of this species in the British Museum. This formed part of the Cumingian
collection, and, like the majority of Mr. Cuming's specimens, has been spoilt through over-
cleaning, nearly aU the microscopic sculpture being destroyed. It diflers from the shells
under examination in having the posterior ear of the left valve slightly larger, and the
scales upon the riblets rather fewer. Both valves, but especially the right, have a number
of dark and pale brown spots, due probably to living in shallower water than the
Challenger specimens.

(?) Pecten lenmiscatus, Keeve.

Pecten lentiginosus, Reeve, Conch. Icon., vol. viii. pi. xxxv. fig. 170 {non species 76).
Pecten lemniscatus, Reeve, op cit., Errata at end of Index.

Habitat. — Samboangan, Philippine Islands, on Reefs, in 10 fathoms.

The single Challenger shell is considerably like the t3rpe in the British Museum, but
exhibits in the grooves between the ribs a fine shagreen-like sculpture which I do not
find in the specimen referred to, the only one I have been able to examine, and which,
having been rather over-cleaned, may have lost its more delicate ornamentation.
Reeve's description of the right valve is not altogether clear. He says it is " ecostata,
undique lirata, squamis brevibus abrupte nodulosis." The ridges are in fact more equal
in thickness than in the other valve, of which in size they about equal the smaller ones.
They are closely squamate, and the scales being worn off' to a great extent have to the
naked eye a finely nodulous appearance.

REPORT ON THE LAMELLIBRANCHIATA. 299

Pecten undttlatus, Sowerby.

Peden nndulatus, Sowerby, Thes. Concli., vol. i. p. GO, [jI. xix. figs. 206, ;07.
Pecten undul((tus, Reeve, Conch. Icon., vol. viii. pi. .kx. fig. 73.

1 = Pecte7i tasmanicus, A. Adams and Angas, Proc. Zool. Soc. I.ond., 1863, p. iif^, pi. xxxvii.
figs. 21, tf, b.

Habitat. — Station 162, off East Moncoeur Island, Bass Strait, iii 38 fathoms
(Challenger) ; Tasmania (Brit. Miis.).

This species is not the same as Pecten jlexuosus, Poli, as stated by Weinkauff
(Conch. Mittelm., vol. i. p. 258), nor would he have considei-ed it as such had it been
properly characterised in the first instance. The minute shagreened sculpture is verj-
peculiar, at once distinguishing it from the European form, and as descriljed by Adams
and Angas in res^^ect of Pecten tasmanicus, which, I believe, will prove to belong to the
same species, it is very like that of Pecten hifrons. The auricles are very unequal,
notwithstanding the statement of Messrs. Adams and Angas to the contrary, whose
figure, moreover, depicts them of diff"erent dimensioias, but not so unequal as in the
types figured by Sowerby and Reeve, and in a single specimen from Ta^^mnnia in tln'
British Museum.

The ribs are somewhat variable in number, and the colour of the left vahe is rather
inconstant. The right valve appears to be always white, or only a little tinted with
purple-pink. The interior of the valves in a great measure corresponds in colour with
the exterior, the right being purplish-pink and the left chiefly white.

I am not sure that Pecten tasmanicus is the same species as Pecten undulatus, fur
the fine riblets, judging from the figure, appear to be coarser ; but the locality and
microscopic sculpture, being similar, point to the conclusion that they are both forms
of one rather variable species.

Pecten leopardus, Reeve (var. Solaris).

Pecten leopardus. Reeve, Concli. Icon., vol. viii. pi. xxxii. fig. 1 15.

Perten leopardus, Smith, Report "Alert" Coll., p. 114.

Var. = Pecten kuhnholtzi, Bcrnardi, Journ. Conch., 1860, vol. viii. p. 378, pi. xiii. fig. 1.

Var. = Pecten Solaris, Sowerby («o« Born) Tlies. Conch., vol. i. p. 55, pi. xii. figs. 7, 8, 22.

Pecten Solaris, Dunker, in Philippi's Abbild., vol. i. p. 202, pi. ii. fig. 2.

Pecten Solaris, Reeve, op. cit., pi. xxiii. fig. 92.

Habitat. — Station 208, off" the west coast of the Island of Luzon, Philippine Islands,
in 18 fathoms ; blue mud.

The typical form of this species was collected on the coast of Queensland. The
variety kuhnholtzi is New Caledonian, and var. solan's has been found at .Amboina

300 THE VOYAGE OF H.M.S. CHALLENGER.

(Dunker), Macassar and China (Reeve). In tlie " Alert " Report I forgot to mention
that in addition to the diflerence of colouring the typical form also presents a difference
in outline. The auricles are certainly larger than in either of the varieties, and the
sides are more spreading or fan-like. This variation, however, is approached by one of
the specimens of var. hunlioltzi in the British Museum, and I have little doubt that had
I a large series for examination I should find many intermediate forms, and should also
probably observe tliat each variet}^ as a rule maintains its special shape.

Pecten senatoi^ius (Gmelin), var.

Odrea senatoria, Gmelin, Syst. Nat., p. 3327.

Pecten senatorius, Sowerby, Thes. Conch., vol. i. p. 74, pi. xvii. fig. 151, and pi. xviii. figs.

188-192.
Pecten senatorius, Eeeve, Conch. Icon., vol. viii. pi. xxi. fig. 81.

Habitat. — Stations 203 and 208, Philippine Islands, in 20 and 18 fathoms.

The single specimen from Station 208 and two from 203 differ from each other in
colour and also somewhat in sculpture. Both forms are also very unlike the Pecten
seJiatorius, as figured in Reeve's work as regards colour, but after careful consideration
and comparison I do not think it advisable to separate them. The former specimen has
more the general appearance of Pecten layardi, Reeve, the other two more resembling
Pecten rugosus of Sowerby. There is a large group of species which requires careful
investigation, and which probably could be considerably reduced in number. It
comprises Pecten senatorius, Pecten criientatus, Reeve, Pecten gloriosus, Reeve, Pecten
crassicostatus, Sowerby, Pecten nobilis, Reeve, Pecten layardi. Reeve, Pecten cristidaris,
Adams and Reeve, Pecten rugosus, Sowerby, Pecten triradiatus. Reeve, Pecten
testudineus, Reeve, Pecten cloactus. Reeve, Pecten miniaceus, (Lamk.) Sowerby, Pecten
jJseudoUma, Sowerby, Pecten hlandus, Reeve, Pecten fricatus. Reeve, Pecten reticulatus,
Reeve, and Pecten saniosus. Reeve. The small forms may possibly be but young shells
of the larger ones, for we do not know the limits in size of many of the exotic species.

Pecten corallinoides, d'Orbigny.

Pecten corallinoides, d'Orbigny, in Webb and Bertholot's Hist. Nat. Canaries, voL ii. pt. 3.

p. 102, pi. vii. figs. 20-22.
Pecten corallinoides, Sowerby, Thes. Conch., vol. ii. p. 65, pi. xii. figs. 3, 4.

Habitat. — St. Vincent, Cape Verde Islands, in 7 to 20 fathoms ; and Teuerife, in
70 fathoms (Challenger) ; Canary Islands (d'Orbigny).

The shells of this species, of Pecten noduliferns, Sowerby, and Pecten nodosus,
Linn., are very much alike, and, what would not be expected, a greater similarity exists

REPORT ON THE LAMELLIBRANCHIATA. 301

between tlie two first, wliieli are fuuiul on opposite sides of Africa, than between the first
and last, inhabitants of different parts of the same ocean.

Pecten amicus, n. s^j. (PI. XXI. fig. G).

Testa compressa, aurantiaco-rufescens, umbones versus albida, costis octo latis
rotundatis, liris pluribus tenuibus squamuhitis ornatis, instructa ; interstitia profunda,
angusta, minute et pulcherrime reticulata. Auricula postica valv^e dextr« minima, antiea
mediocriter magna, inferne baud profunde siuuata, antice oblique curvata, liris radiantibus
tenuibus circiter sex, incrementique lineis sculpta.

Only a single valve of this species, and that evidently immature, is at present known.
The sculpture being so remarkable, I do not hesitate to describe it as new.

It is narrow, compressed, slightly unequal sided, the posterior slope being a little
longer than the anterior, and like it nearly rectilinear, together forming an apical angle of
about seventy degrees. It is of an orange-reddish tint, gradually paler towards the
umbones, and has eight broad rounded ribs which are moderately elevated, " and orna-
mented with several very slender prickly-scaled liri^. The grooves between the ribs are
narrow, deepish, and ornamented with an excessively fine regular square-meshed network.
The auricles are very unequal, the posterior being very small indeed, whilst the anterior
(in the right valve) is fairly large, obliquely curved in front, not deeply sinuate beneath,
and bears about six fine radiating liroe, which are crossed by the lines of increase. The
interior exhibits more or less of the external tinting, which, however, in a more mature
shell, would probably be less vivid.
' Length 12 mm., height 14^, probable diameter of the perfect specimen 4.

Habitat. — Station 172, off Nukalofa, Tongatabu, in 18 fathoms.

Pecten tigris and Pecten jxs-felis are rather like this species in general appearance,
but differ in the detail of the sculpture, both of them being finely Urate in the sulci
between the ridges and sculptured with a difterent mici'oscojiic ornamentation.

Pecten testes, Bivona.

Pecten tedm, Bivona, Philippi, Enum. Moll. Sicil., vol. i. p. 81, pi. v. fig. 17, vol. ii. p. 57.
Pecten sfriatus, var. fartivus, Forbes and Ilauley, Brit. Moll., vol. iv. pi. li. tig. 2.

Habitat. — Station 75, off Fayal, Azores, in 450 fathoms ; volcanic mud.

Only a single valve was obtained of this species, which has not, I believe, been recorded
from so southern a locality. It exactly agrees with ]\Iediterranean specimens with which
I have compared it, being quite smooth, with th(.' exception of flic microscopic decussation
as described hy Philippi.

302 THE VOYAGE OF H.M.S. CHALLENGEE.

Pecten kermadecensis, n. sp. (PL XXI. figs. 7-7«).

Testa fragilis, tenuissima, pellucida, valde compressa, valvis diverse sculptLs. Valva
dextra liris gracillimis confertis concentricis instructa, sinistra liris concentricis magis
distautibus radiatimquc pulcherrime squamulatis ornata. Auriculfe inaeqnales, anticis
majoribus, in valva dextra autica inferne sinuata, porca angusta marginata. superne
cristulata. Umbones mediocriter acuti, lateribus divergentibus rectis.

Only two valves described above were obtained, and it is even possible that they do
not both belong to one and the same species. They are about as long as high, very thin
and fragile, transparent whitish, very much flattened, and ornamented with different
sculpture. The right has fine close-set concentric lirse, which become a trifle more
pronounced as the shell increases. The left also bears numerous rather more remote and
more elevated concentric lirse, supporting many radiating series of small scales, of which
one or two indications are visible in the right valve. The ears are unequal, the antei'ior
being conspicuously larger than the posterior. The front one in the right valve is
sinuated beneath, and is margined along the oblique dorsal slope by a smoothish ridge,
which is concave ou the reverse side. The lines of growth are conspicuous on the ears,
and in the right valve are produced upward, forming a crested edge to the hinge-line.
The beaks are moderately acute, having an apical angle of about 108°, the converging
lines being rectilinear.

Length 7^ mm., height 7^, diameter 2^.

Habitat. — Station 171, north of Kermadec Islands, at a depth of 600 fathoms.

This is a fragile species, and probably, living at such a depth, never becomes much
thickened.

Pecten pudicus, n. sp. (PI. XXI. figs. 8-8^).

Testa tenuissima, planulata, paulo iugequivalvis, albida, hand nitida, concentrice valde
plicata, plicis utrinque attenuatis, undique confertim et tenuiter lirata. Auriculae
insequales, anticis majoribus, antica valva; dextras liris gracilibus paucis squamulatis
ornata, inferne profunde sinuata.

Length 18:^ mm., height 20, diameter 5.

Habitat. — Station 146, east of Marion Island, in 1375 fathoms; Globigerina ooze.

This beautiful species is very like Pecten fragilis of Jeffreys, but appears to differ
somewhat in form and in having both valves similarly plicate and lirate. The auricles
also are not " equal in size," the anterior being decidedly larger than the posterior.

The right valve is rather flatter than the left, and its anterior auricle is deeply incised
underneath, the upper half of it being ornamented with four or five finely squamate
slender lirae.

REPORT ON THE LAMELLIBRANCHIATA. 303

Pecten murrayi, n. sp. (PI. XXII. figs. I -la).

Testa iiTogulariter cireularis, comprcssa, tonuissimi), subliyalina, insequivalvis, sordide
albida. Valva dextra fere plana, incrementi lineis toiuiil)Us striata, sinisti'a jjaulo convexa,
liris numerosis regularibus conceutricis tenuissimis instructa. Auriculae valvae sinistrae
fere sequales, postica latere posteriori coutiuua ; antica valvse dextrse parva, inferne
mediocriter profunde sinuata, sinu callo teuui iuduto. Pagina interna nitida.

Length 15 J mm., height 14|^, diameter 2.

Habitat. — Station 184, east of Cape York, North Australia, in 1400 fathoms.

In this very flat species the hinge-line occupies about two-fifths of the whole length
of the shell. The valves are difi'erently sculptured, the concentric lirse of the deeper or
left one lieiug stronger than those in the right. In this, in addition to the concentric
sculpture, minute interrupted lines which radiate from the apex are discernible under the
microscope, and within it is slightly nacreous.

Pecten vitreus (Chemnitz).

Pallium viireum, var. papi/raceiim, Chemnitz,' Conch. -Cab., vol. vii. pp. 267, 335, pi. Ixvii.

fig. 637a.
Palliuin vitrcum, Schrdter, vp. cit, Index, p. 78.
Peden vitrexis, Philippi, Abhaudl., vol. i. p. 203, pi. ii. fig. 3.
Pecten vitreus, Jeffreys, Brit. Conch., vol. v. p. 168, pi. xcix. fig. 6.
Peden vitrens, Sars, Moll. Reg. Arot. Norv., p. 21, pi. ii. figs. 5a, 5b.

Habitat.— Stations 307, 308, 310, and 311, all off the west side of Southern
Patagonia, in 140 to 400 fathoms; Station 232, South Japan, in 345 fathoms; and
Stations 204, 207, and 209, all off the Philippine Islands, in 100 to 700 fathoms.

The specimens from Stations 307 to 311 have already been associated with this
species by Jeffreys, and although I have only had an opportunity of comparing them
with two northern examples, there seems also, judging by the descriptions and figures,
no reason for questioning the identification. The mantle is finely papillose, and furnished
with minute black-ringed ocelli. Pecten fragilis, an allied form, is said by Friele to be
devoid of this characteristic.

These Patagonian specimens appear to be quite t}"pical examples of the species.
Having the same form and the surface covered more or less with the interrupted rows of
scales. The single example from South Japan has very little of this squamate character,
being only about half-grown, but in foi-m and the microscopic sculpture agrees perfectly
with the normal tj^pe of the species. Pecten vitreus, King (Zool. Journ., vol. v.), from
Patagonia, is a totally different shell.

The shells from the Philippine Islands have very numerous rows of scales which ai-e
rather longer than in other specimens of this species which I have examined.

304 THE VOYAGE OF H.M.S. CHALLENGEK.

With this exceptiou, and a very slight variation iu the microscopic sculpture, there
do uot at present appear to be any further or sufficient grounds for specifically separating
the Philippine examples. If we had a more extended series of specimens for examination,
it is possible further difi"erences would present themselves.

Pecten suhhyalinus, n. sp. (PI. XXII. figs. 2- 2a).

Testa compressa, tenuissima, vitrea, nitida, aliquanto intequivalvis ; valva sinistra
paulo convexior, fere la^vis, striis paucis concentricis aliisque radiantibus sculpta ; valva
dextra striis concentricis regularibus ornata. Auriculse infequales, bene definitaa, anticis
paulo majoribus, ilia valvas dextraj radiatim lirata, mediocriter profunde sinuata. Margo
valvse infra sinum rectilinearis, haud denticulatus.

Length 7 mm., height Ih, diameter 2.

Habitat. — Station 310, off the w'est coast of Southern Patagonia, in 400 fathoms.

This species belongs to the same group as Pecten vitreus (Chemnitz), from which it
differs both in sculpture and form. In that species the posterior auricles are scarcely
defined, whilst in the present form there is a well marked umbonal rectilinear ridge,
from the apex to the side margin. The anterior umbonal slope in that species is incurved
and toothed, in this it is straight and edentulous.

Pecten distinctus, n. sp. (PL XXII. figs. 3-3a).

Testa parva, compressa, paulo ina3quivalvis, tenuis, subpellucida, haud nitida, sordide
albida. Valva dextra parum convexa, concentrice tenuissime lamellato-striata, sinistra
paulo convexior, liris concentricis fortioribus instructa, liris radiantibus paucis indistinctis
ornata. Auriculae insequales, definitse, anticis majoribus, ilia valvse dextrce radiatim
lirata, inferne haud profunde sinuata.

This little species is slightly inequivalve, the left valve being rather deeper than the
other. It is compressed, thin, a little transparent, not glossy, of a dirty white colour,
and has difi"erently sculptured valves. The right has much finer concentric lirse than the
left, and has no radiating lines, which, however, are not particularly conspicuous in
.the other valve. The umbones are rather acute, the straight or feebl)^ incurved sides
forming an apical angle of about 105°. The ears are unec[ual, the front ones being the
larger. That in the right valve is ornamented with six or seven fine lirse, which cover
the greater part of the surface, leaving only a narrow plain groove at the moderately
deep sinus.

Length 8 mm., height 7\, diameter 2.

Habitat. — Off Marion Island, in 100 fathoms.

In this species the ears are depressed and well marked off from the rest of the surface.

REPORT OiV THE LAMELLIBRANCHIATA. 305

Pecten clathratus, Martens (PI. XXII. figs. 4-4o).

Pedeii clathratus, Martens, Sitzungsb. d. Gesellsch. natuif, Freundi-, IJerlin, 1881, p. 79.

Testa tenuis, subpfUucida, iutequivalvi.y ; \alva de.xtra planiuscula, parum nitida,
incrementi lineis striata, striisque microscopicis radiantibus, inidique suljcancellata ; valva
sinistra profundior, lanicllis coucentricis, tenuibus, lirisquc iiimicrosis radianti1)us fili-
formibus cancellata. Auriculae fere jequales, antica valvse dextr?e lamellis incrementi
sculpta, ad extremitatem rotundata, inferue profunde siiiuata.

This species is considerably inequivalve, thin, rather pellucid and compressed. The
right valve is only a little convex, and, as it were, fits within the other valve, although in
reality its outer margin, which is upturned, does extend to the edge of the left valve. It
is a little glossy, sculptured 'svith very fine lines of growth, and has a microscopic,
subgranular, radiating structure. The left valve is much deeper and ornamented with
stronger sculpture, consisting of very fine concentric lamellae and still finer and more
numerous radiating ones, together producing a pretty cancellated appearance. The ears
are not very unequal, tlie anterior being only a little larger than the posterior. The
front one in the right valve is broadly curved at the end, rather deeply cut in under-
neath, and sculptured with strongish lines of growth. The umboucs are acute, the sides
forming an apical angle of about 100 degrees.

Length 3^ mm., height 3;^, diameter 1.

Habitat. — Oft' Christmas Harbour, Kerguelen Island, in 120 fathoms.

The shells obtained at this locality apparently belong to tlie Pecten clathratus of
von Martens, Ijut as 1 am not absolutely certain I have deemed it advisable to give the
above description.

Pecten aviculoides, n. sp. (PL XXII. figs. 5-5«).

Testa parva, vakle inajquivalvis, paulo obliqua, tenuis, sordide albida. Valva dextra
planiuscula, nitida, striis incrementi tenuissimis sculpta, sculptura microscopica sub-
reticulata ornata. Valva sinistra profunda, lamellis coucentricis, validis, costisque ad octo
radiantibus fortiter cancellata. Aniiculne subfequales, auricula valvar dextrae antica
lamellis incrementi liriscjue paucis radiantibus instructa, inferne subprofunde sinuata.
Linea cardinis longa, longitudinem totam testa) a;quans. Umboncs centrales, ille valvag
sinistra^ paulo supra marginem productus.

This species is remarkable for the great difference in the sculpture of the valves. It
is rather like a minute Avicula in form, slightly oblique in growth, very inequivalve,
thin, and of a dirty white colour. The right valve is very slightly convex at the centre,

(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 39

306 THE VOYAGE OF H.M.S. CHALLENGER.

and fits, as it were, within the other valve, its very thin margin being npcurved and
api^ressed to the outer edge of the other valve. It is sculptured with a few lines of
gro\\i:h, and has under the microscope a minutely shagreened appearance. The left valve
is much deeper, and ornamented with coarse concentric lamellae, which, crossing about
seven or eight strongish radiating \ivsd, produce a coarsely cancellated surface. The
ears in this valve have only the concentric lamellse and are al)0ut equal in size, the
posterior being sinuated at the side. The anterior auricle in the right valve is orna-
mented with concentric lamellae of growth which cross a few radiating ridges, and it is
rather deeply cut in beneath. The hinge-line occupies the whole length of the shell, and
above the centre the umbo of the left valve is slightl)^ prominent.

Length 2 mm., height 1|, diameter |-.

Hahitat. — Prince Edward Island, in 100 to 150 fathoms.

The shell here described is probably not adult ; but as the sculpture of the valves is
so markedly different and not like that of any other species with which I could compare
it, I do not think it hazardous to name it.

Pecten culehrensis, n. sp. (PL XXII. figs. G-Go).

Testa compressa, paulo insequivalvis, teuuissima, semipellucida, altior quam longa.
Valva dextra parum convexa, lamellis numerosis concentricis, plus minusve radiatim
squamulatis, ornata. Valva sinistra leviter convexior, liris tenuibus radiautibus et
concentricis confertim cancellata, et nodulosa. Auriculae inaequales ; antica valvas dextrae
superne cristata, ratliatim lirata, inferne mediocriter profunde sinuata.

This is a very compressed species, very thin, semitransparent, slightly inequivalve,
and higher than long. The right valve is a little flatter than the left, and sculptured
with numerous fine concentric lamellae which are more or less ornamented with small
scale-like projections disposed in radiating series. When these are broken off the lamellae
have a frilled appearance. The left valve has a somewhat coarser sculpture, which
consists of slightly stronger concentric lira3 and numerous radiating ones, some of which,
at irregular intervals, are thicker than the rest, the points of intersection of all, but
especially the stronger ones, with the concentric lirse being jjrettilj^ nodulose. The ears
are rather unec^ual, the anterior as usual being the larger. That of the right valve is
rather strongly sculptured with lamellae of growth (produced above into a crest along the
hinge-line) and a few somewhat feeble radiating ridges. The umbones are rather acute,
having the sides, of which the anterior is rather straighter than the posterior, converging
to an apical angle of about 95 degrees.

Length 8^ mm., height 9^, diameter 2|.

Habitat. — Station 24, off Culebra Island, AVest Indies, in 390 fathoms ; Pteropod ooze.

REPORT ON THE LAMELLIBRANCHIATA. 307

Pecten sp.

Habitat. — Station 24, off Culcljia Island, "West Indies, in HDO fatlioms ; Pteropod ooze.

A few odd valves of a thin subpellucid Pecten were dredged at this Station wLidi
appear to belong to an undcscribed species. As they are in rather poor condition, and
I am uncertain whether I have correctly paired the valves, or have associated together
the right and left valves of two distinct forms, I have refrained from naming them. The
right valves are about as convex as the left, and sculptured with very many regular
concentric striae. The left valves to a great extent have the sculpture worn oft", but what
remains consists of more distant concentric lamellae and radiating thread-like lirse. The
auricles are unequal, the anterior being the larger, and that in the right valve has a
radiating ridge or two crossed by the lines of growth. The length is 4 mm. and the
height about the same.

Pecten sp.

Habitat. — Station 24, otfCulebra Island, West Indies, in 390 fathoms ; Pteropod ooze.

A single right valve only was obtained of this species, which I cannot identify with any
as yet known. It is quite flat, glossy, irregularly concentrically waved or plicate, and
devoid of any sculpture except upon the front auricle, which has the upper half
ornamented with four or five finely squamate lirse. It is 9 mm. in length and 10 in height.

Pecten {Janira) fumatus, Reeve.

Pecten fumahis, Eeeve, Coiicli. Icon., vol. viii. pi. vii. fi^. -'i.
Void fumata, Angas, Proc. Zool. Soc. Lond., 1867, p. 933.

Habitat. — Port Jackson, New South Wales, in 2 to 10 and 4 to 1 8 fathoms.

This species is peculiar for its almost uniform sombre colour. The deep valve is,
however, generally somewhat paler towards the umbo, and the flat valve also occasionally
exhibits a whitish patch in the same region. The interior is white, especially the convex
valve, but stained with burnt brown on the ears and towards the outer margin. The
epidermis, principally on the concave valve, is closely concentrically lamellated and
somewhat fibrous.

Pecten {Janira) laqueatus, Sowerb)".

Pecten laqueatus, Sowerby, Thes. Couch., vol. i. !>. 46, pi. xv. lig. 101.

Pecten laqueatus, Reeve, Conch. Icon., vol. viii. pi. xxs. fig. 13.5.

Pecten laqueatus, Lischko, Japan. Meer.-Conch., Theil i. p. 1G7, Theil ii. p. 157.

Vola laqueata, Dunker, Ind. Moll. Japon., p. 243.

Pecten antonii, Pliilippi, Abbild., vol. i. p. 99, pi. i. figs, la-lc

Habitat. — Station 233a, off Kobe, Japan, in 50 fathoms ; blue mud.

308 THE VOYAGE OF H.M.S. CHALLENGER.

This very fiue species has also been recorded from Yedo, Nagasaki, and Hakodadi, and
probably does not extend to California as stated by Reeve.

Amussium, Klein.
Aimissiu7n plenronectes (Linne).

Ostrca pleuronedes, Linii6, Syst. Nat., ed. 12, p. 1145.

Pcden pleKronectcs, SowerViy, Thes. Concli., vol. i. p. 55, pi. xvi. figs. 127, 128, 135, 136.

Peden pleiironedes, Reeve, Conch. Icon., vol. viii. pi. xiii. fig. 48.

Habitat. — Station 203, Philippine Islands, in 20 fathoms ; and Station 188, south of
New Guinea, in 28 fathoms.

The Philippine specimens of this well-known species are like that figured in Reeve's
work, but those from the North Australian region have the coloured valve curiously
ornamented with angular In-own markings, disposed somewhat regularly in radiating
series, and towards tlie umboncs the minute white dots which are usually noticeable are
arranged in rays also.

Amussium dalli, n. sp. (PI. XXII. figs. 7-7c).

Testa tenuissima, compressa, hyalino-albida, sequivalvis, elongata. Valvar sculptura
diversa ornatse, altera (? dextra) conspicue nitente, incrementi lineis striisque tenuissimis
sculpta, altera liris concentricis tenuibus ornata, undique minutissime cellulosa. Auriculae
parvse, subsequales, utrinque acute angulataj, in valva dextra lateribus paulo concavis.
Pagina interna fulgens, liris undenis radiantibus albis hand nd marginem productis instructa.

This species is longer from the beaks to the lower margin than from side to side. It
is almost equivalve, the smoother valve, which I regard as the right, being perhaps a
trifle more swollen than the other. It is a very thin fragile shell, semitransparent and
very glossy, particularly the right valve, which has a more glossy appearance than the
left, the latter lieing of a somewhat thicker texture and of a dilute milky white colour.
The valves are differently sculptured. The right merely exhibits the fiue concentric
lines of growth and very fine radiating substrise. The left is more beautifully ornamented,
being concentrically closely and finely Urate, and throughout microscopically shagreened,
the outer or surface-layer being composed of countless excessively minute closely packed
crystal-like bodies having unequal sides, varying in number from four to six, and flat
outer and basal sui'faces. The beaks are acute, and converge to an angle of about
110 degrees. The ears are small, about equal on both sides, slighty concave laterally
in the right valve. The interior is very glossy, strengthened liy eleven fine
radiating co.stellse, which, with the exception of the two very short uppermost, only
extend about half-way across the surface of the right valve, and rather further in the
left, in which also they are a trifle thicker.

REPORT ON THE LAMELLIBRANCHIATA. 309

Length 48 mm., height 52, diametei' 8.

Habitat. — Statiou 33, oft* Bermu(Li.s, in 435 i'uthoras ; coral mud.
This fine species is dedicated to Mr. W. H. Dall as a mark of high esteem on
account of his many and valuabh) papers on raahicology.

Amussium watsoni, n. sp. (PL XXIL figs. 8-8c).

Testa tenuissima, subdiaphana, alliiihi, paido inajquivalvis, sul)circularis, sericato-
nitens, utrinque conspicue hians. Valvte compressre, diverse sculptse. Valva dextra
profundior, paUidissime fuscescens, liris confertis eoncentricis prope marginem angus-
tissime himelLatis ornata, sinistra similiter lirata, sed etiam liris gracilibus radiantibus
umboncs vei'sus prsecipue cancellata. Auriculae parva3, increment! lineis aliisque
radiantibus instructse. Pagina interna nitida, marginem versus leviter iridescens, liris
albis radiantibus 10-12 baud ad marginem extensis munita.

This charming species is almost circular, very thin and fragile, considerably
gaping on both sides above the middle, a little inequivalve, the one valve which
I regard as the right being a trifle more swollen than the other. It is also a trifle
thinner and of a very light brownish tint. The left valve is of a milky white colour,
and consequently rather less transparent. The exterior of the valves is beautifully
glossy and has a silky appearance. Both are very finely, concentrically lirate, the
hrse towards the outer margin in the right valve being very narrowly lamellated. In
addition to this ornamentation the left valve exhibits numerous fine radiating liras,
which are decidedly elevated for a short distance around the um bones, and then
gradually, further out, take the form of faint substriations. The ears are of moderate
size, al)out equal on each side, and sculptured with elevated lines of growth and others
diverging from the beaks, the former sometimes forming a sort of serrate dorsal edge.
The umbones are moderately acute, with an angle of divergence of about 125 degrees.
The interior is glossy, somewhat iridescent around the margin, and strengthened with
from five to six pairs of white riblets of dilferent lengths, the longest becoming obsolete
at some distance from the circumference.

Length 50 mm., height 52, diameter 9g.

Habitat. — Station 218, north-east of New Guinea, at a depth of 1070 fathoms.

This lovely species, one of the prizes of the Expedition, I feel much pleasure
in naming after my friend the Rev. R. P)00g Watson.

Amus.num caducum, n. sp. (PL XXIII. figs. 1-lc).

Testa tenuissima, pellucida, rotundata, compressa, superne angustata, producta, paulo
ina^quivalvis (valva dextra sinistra leviter convcxiore) utrinque cons])icue hians. Valva

310 THE VOYAGE OF H.M.S. CHALLENGER.

dextra polita, concentrice exilissimc striat;i, striisquc radiautibus obsolctis sculpta ;
sinistra iiitida, concentrice minuta lamellata, minutissimequc radiatim striata. Auricuht'
mininioe, subseciiuiles. Pagina interna nitida, lii'is aJl)is tenuibus denis instrncta.

This species is rather higher than hmg, romuloil, Imt narrowed and produced above.
It is very thin, slightly inec[uivalve, gaping considerably on both sides, glossy, pellucid
around the outer margin, and rather thicker and more opaque towards the beaks. The
right valve is the deeper, somewhat more shining than the left, exhibiting very fine line;^
of growth and indistinct radiating substriations. The left valve is more strongly concentri-
cally sculptured, and the radiating stride are more dense and stronger'. The auricles are
very small and almost of the same size. The beaks are acute, forming an apical angle of
about 105 degrees, the converging dorsal lines being sliglitl}- concave. The interii)r of the
valves towards the umbones, and rather more than half way across the valves, is more
opaque than exteriorly, and is strengthened by ten white slender brae of different lengths.
The outer pellucid zone of the right valve is very prettilj' blue-prismatic within.

Length 20 mm., heioht 22, diameter 4i.

Habitat. — Station 207, west of the island of Luzon, Philippines, at a depth of 700
fatlioms ; blue mud.

The chief characteristics of this species Ijesides form, are its fragility, fine sculpture,
glossy surface, and the ten radiating costellse. The right vnlve is somewhat yellowish,
and the left whiter.

AmussiiDii jejfrei/sii, n. sp. (PI. XXIII. figs. 2-2t).

Testa tenuissima, paulo inajquivalvis, oldique rotunde ovata, utrinque conspicue hians,
subnitida, valvis dissimiliter sculptis, divcrseque coloratis dextra superru' in medioque
aurantiaca, marginem versus pallida diaphaua, radiatim teuuiter lirata, incrementique
lineis ornata, valva sinistra superne in medioque quam dextra pallidiore, inferne pellucida,
concentrice tcnuiter lirata. Auriculae parvas, subajquales, ad latera obliquae, postica
valvse sinistrse cseteris leviter dissimile. Pngina interna nitens, liris radiantibus
insequalibus albis abrupte terminatis circiter 15 instruct;!.

This very beautiful species is higher than long, compressed, gapes considerably
at the sides, is slightly oblic^ue, roundl}- ovate, and a little inec[uivalve. The valves are
very thin, somewhat differently coloured, and ornamented with different sculpture. The
deeper valve (regarded as the right) is more brightly coloured, having the upper and
central portion tinted bright orange, and the outer l)order very much paler and
transparent. It is sculptured with numerous fine rounded lirse which radiate from the
beak and extend almost to the circunifercnee all round. In addition it is marked with

EEPORT ON THE LAMELLIBRANCHIATA. 311

fine concentric lines of gi'owtli, producing, chiefly towards the uml>o, a distinctly
cancellated surface. The other valve is much paler than the right, and adorned
throughout with numerous fine concentric lirae. The hcaks are acute, converging with
slightly concave sides to an angle of aliout 114°. The cars are small, al)Out equal on
both sides, feebly sculptured with stria} of growth and oblique at the sides. The
posterior of the left valve diflfers from the rest in having a very small sinus where it
joins the dorsal slope of the valves. The interior is coloured like the outside very gloss}',
and strengthened with about fifteen Avhite radiating lirse which terminate abruptly and
extend over the tinted porti(.)n of the valves. Some of them in certain specimens are
very short, and are not produced towards the beaks like tlie rest, which gradually
attenuate upwards.

Length 191- mm., height 21-i, diameter 5.

Habitat. — Station 210, Philippine Islands, in 375 fathoms; blue mud.

This species is remarkable for the orange colour of the right valve and the fleshy tint
of the left, also for the strongisli and abruptly terminating internal lirag. I name it w-ith
much pleasure after my late friend Dr. Gwyn Jeffreys, of " British Conchology " renown.

Amussium tom'.'^i, n. sp. (PL XXIII. figs. 3-Sh).

Testa parv^a, compressa, tenuis, subpellucida, alba, le\iter injequivalvis, valvaj
diverse sculptse, marginil)us superuis levissime concavis. Valva (dextra ?) paulo con-
vexior, nitida, iucrementi lineis minime conspicuis sculpta, sinistra lii'is confertis
tenuissimis concentricis oruata. xVuriculaj jjarum insequales, postica paulo majore, in
valva sinistra striis paucis radiantibus prope marginem obliquum dorsalem signata.
Pagina interna nitens, radiis tenuissimis duodenis inasqualibus instructa.

This species, so far as at present known, appears to he of small size. It is very
thin, scarcely gaping at the sides, slightly inequivalve, very much compi-essed, and
semitransparent white. The valves are about as long as high, have acute beaks and
faintly concave dorsal slojjes, the ajtical angle being of about 105 to 110 degrees. The
valve regarded as the right is a trifle deeper than the other, and nearly quite smooth
and glossy, exhibiting only the feeblest indications of lines of growth, the left valve,
on the contrary, being prettily ornamented with very fine and close-set concentric
liraj. The auricles are unequal in size, the posterior being considerably larger, that of
the left valve exhibiting a few (two or three) striae near the dorsal slope. The
interior is glossy, and strengthened with twelve slender radiating liras, of which the
two uppermost are very small and insignificant.

Length 8 mm., height 8^, diameter 2.

312 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat. — Station 185b, cast of Cape York, North Australia, in ].'35 fatlioms ; coral
sand.

This species differs from Amussium caduciim not only in having more internal
costella3 but also in form and the sculpture of the exterior.

Amussium scituhim, n. sp. (PI. XXIII. figs. 4-46).

Testa (juveuis ?) parva, compressa, all)a, tenuis, subfequivalvis. Valva dextra
lineis incrementi paucis hie illic cisteris majoriljus instructa, sinistra liris numerosis
radiantibus, aliisque minus conspicuis concentricis concinne cancellata. Auriculae
mediocres, paululum ina^qnales, antica valvse dextrae prope marginem obliquum
dorsalem canaliculata, lirisque radiantibus paucis subgranulosis ornata, et antica et
postica in valva sinistra cancellatis. Pagina interna liris tenuibus circiter denis ad
marginem productis instructa.

Of this species only a few valves were obtained, possibly representing but the
young form of it. It is a thin shell, semitransparent white, a trifle inequivalve, much
compressed, and about as long as high. The right valve is slightly deeper than the
left, and sculptured only with the concentric lines of growth, of which a few are more
raised than others. The left valve, in addition to the raised lines of growth, has a
considerable number of fine radiatiuo- lirse, Qjiviusr the surface a more or less cancellated
appearance. The beaks are acute, the converging dorsal lines meeting at an angle of
about 90 or 95 degrees. The ears are a little unequal, the anterior of the right valve
being somewhat channelled close to the oblique dorsal slope and ornamented with a few
radiating raised lines which are somewhat granular or subsquamous through being
crossed by other raised lines of growth. The posterior auricle in this valve, on the
contrary, is almost destitute of sculpture. Both ears in the left valve have radiating
and cross lirjE, the former predominating, and being, on the anterior auricle, prettily
scaled near the dorsal slope. The internal liraj are ten in number and produced to the
outer margin, where sometimes they are slightly thickened.

Length 4i mm., height 4^, diameter 1^.

Habitat.— Utatioii 188, south of New Guinea, in 28 fathoms; green mud.

This sijecies differs from Amussium torresi in sculpture and the number of
internal ridges.

Amussium squamigerum, n. sp. (PI. XXIII. figs. 5-5o).

Testa ecjuilateralis, couvexiuscula, rotundata, alba, subpellucida. Valva dextra
concentrice laminata, iamellis teuuissimis numerosis supra porca? nonnullas radiantes

EEPORT ON THE LAMELLIBRANCHIATA. 313

obsoletas pulcherrimc squamatis. Umbones parvi, acuti, Isevigati ; auriculae paulo
insequalos, postico majori, incrementi lineis lamellatis radiisque obsoletis divergcntibus
instructi. Lirse interuaj undecim gracillimse, extremitatibus parum incrassatis.

This species, of which only a few right valves are at present known, is a little convex,
equilateral, rounded, but rather longer from the hinge to the ventral margin than across
from side to side. It is very thin, whitish, and slightly pellucid. The right valve is
sculptured with numerous very fine concentric laminae, which are altogether wanting on
the acute glossy beak, and towards the lower margin, in some instances, become rather
more crowded than elsewhere. They have an undulating character through crossing
slightly elevated radiating ridges. These vary in number according to the size of the
specimen, being about fifteen in small valves, and twice that number in the largest under
examination, every alternate ridge extending only about half-way from the circumference
to the umbo. Upon these rays the concentric lamellse, when not worn, are elevated into
vaulted scales, giving a very pretty appearance to the shell. The ears are small, somewhat
unequal, the front one being rather the larger. They are ornamented with the termina-
tions of the concentric laminae, which pass over two or three obsolete rays, more noticeable
on the posterior than the anterior side. The acuteness of the beak is somewhat variable, the
apical angle of divergence being 100 to 113 degrees. The internal surface is glossy, and
strengthened usually with eleven radiating lirse, but at times here and there an interven-
ing short one is met with. They are very slender, thread-like, scarcely thickened at the
extremities (excepting two or three of the uppermost), and gradually disappear as they
approach the umbonal region.

Length 12 mm., height 13, probable diameter 3.

Habitat. — Station 24, off Culebra Island, West Indies, at a depth of 390 fathoms ;
also Station 33, off Bermuda, in 435 fathoms.

■Amussium obliquum, n. sp. (PI. XXIIl. figs. G-Ga).

Testa compressa, tenuissima, semipellueida, umbones versus nitens, obliqua, irregu-
lariter rotundata. Valva sinistra in^quilateralis, liris coneentricis tenuissimis instructa.
Auriculae valde insequales, postica longe majori, superne acute angulata, inferne ab valva
sulco angusta profundo sejuncta. Umbo mediocriter acutus, latere obliquo postico
longiore. Lirse radiantes internae circiter sedecim, quarum paucae superiores crassiores
videntur.

As but a single minute and probably young left valve is all that is at present known
of this species, it is with considerable hesitation that I have ventured to describe and
impose a name ujDon it.

(ZOOL. CHALL. EXP. PART XXXV.— -1885.) JIlll 40

314 THE VOYAGE OF H.M.S. CHALLENGER.

It is compressed, very thin, semitransparent, of an oblique growth, so that the
hinder side is larger than the anterior. It is sculptured with very slender concentric
lirse, which become mere striae towards the glossy umbo. This is moderately acute,
the converging sides, of which the posterior is considerably the longer, meeting at
an angle of about 122 degrees. The ears are very unequal, the hinder one being
decidedly larger, denticulate along the top, and separated beneath from the umbonal
slope by a narrow deep groove above, parallel with which is an elevated ridge
bordering the auricle. It is acutely angled above and cuts in deeply below. The
interior is strengthened with sixteen radiating ridges, the two uppermost (of which that
on the posterior side is almost obsolete) forming the base of the ears. One or two of the
upper ones on each side are very short, and appear thicker than the rest, although in
reality they are not. None extend to the beak, so it is probable that very young shells
are destitute of lirse.

Length 3 mm., height 2f.

Hahitat. — Station 24, off Culebra Island, West Indies, in 390 fathoms; Pteropod ooze.

This minute valve, although without doubt very young, indicates a species of a
peculiar oblique growth distinct from any as yet known.

Amussium propinqimm, n. sp. (PI. XXIII. figs. 7-76).

Testa valde compressa, tenuissima, pellucida, nitida, rotundata ; valva dextra laevis,
incrementi lineis parum conspicuis sculpta, sinistra radiatim tenuiter lirata. Auriculae
subsequales, lateribus concavis. Pagina interna nitida, luis capilliformibus duodenis
instructa.

This species, of which only two odd valves are at present known, is very fragile,
pellucid, much flattened, glossy, and about ecjuilateral. It is of a rounded form, perhaps
a trifle longer than high, and has rather a long hinge-line. The auricles are small, not
quite equal, those of the right valve (the only one perfect at this part) being decidedly
concave at the sides, and sculptured with fine lines of growth. The umbones are small,
project a trifle beyond the straight hinge-margin, and have the sides very faintly concave
and converging to an apical angle of about 125 degrees. The right valve is smooth,
exhibiting only very fine lines of increase, which, however, are rather more visible near the
outer margin than elsewhere. The left valve, besides these concentric striae, is sculptured
with numerous fine radiating lirse. The interior of the valves is glossy, and strengthened
with twelve excessively fine hair-like lirse, which attain neither to the umbones nor
to the circumference. The shorter ones beneath the ears are the thickest. The left
valve appears radiately striated within, each stria corresponding with an external lira.
The ligamental pit is very minute.

REPORT ON THE LAMELLIBRANCHIATA. 315

Lengtli 7^ mm., height 6f.

Habitat. — Station 78, east of the Azores, at a depth of 1000 fiithoms ; volcanic mud.

This species, although bearing a general resemblance to Amiissium lucidum, differs
(judging from the only two valves known) in being proportionally shorter from the beaks
to the ventral outline, in comparison with the transverse diameter. Its hinge-line is
longer, the apical angle of the beaks less acute, the left valve is radiately Urate instead
of concentrically striate, the anterior ear in the same valve is quite distinct in form, and
the internal lirse are more slender and fewer than in the Azorean examples of Amussium
lucidum.

Amitssium cancellatum, n. sp. (PI. XXIII. figs. 8-8c).

Testa compressa, parum pellucida, albida, hand polita, sequilateralis, rotundata, paulo
insequivalvis, valvis diverse sculptis. Valva dextra profuudior, liris tenuissimis
radiantibus numerosis aliisque gracilioribus confertioribus concinne canceUata, sinistra
concentrice sulcata, sulcis regularibus, tenuibus, sensim accrescentibus. Auriculae
insequales, posticis majoribus. Umbones acuti, lateribus convergentibus leviter con-
cavis. Linea cardinis brevis, recta, fossa mediana ligamenti parva instructa. Pagina
interna nitens, liris mediocriter fortibus circe 12 (aliis minoribus ssepe interpositis)
munita.

This species is as a rule a trifle longer from the beaks to the lower margin than from
side to side. It is compressed, slightly inequivalve, only a little transparent, whitish,
hardly at aU glossy, and has the valves diflerently sculptured. The right or somewhat
deeper valve is ornamented with numerous fine thread-like radiating lirse, which are
crossed by still finer concentric ones. The former are more slender and closer together
down each side than towards the middle of the valve, and the latter, besides being finer
than the radiating lirse, are also much more approximated to one another, those near the
beaks being further apart than the rest. The left valve has somewhat of a silky
appearance, and is finely and closely concentrically lirate, the lirse gradually becoming
thicker and more remote with the growth of the shell. The auricles are small, somewhat
unequal, the posterior being rather larger than the anterior. They are sculptured with
fine lines of growth and sometimes denticulate at the top. The posterior end of the left
valve is sinuated below, and is separated from the main part of the valve by a deepish
groove, in which a slender ridge runs parallel with the dorsal slope. The beaks are small,
acute, the slightly concave sides converging to an angle of about 117 degrees. The glossy
interior of the valves is strengthened with numerous white fairly strong radiating lir^e,
visible exteriorly, especially in the right valve, which is a little more transparent than the
left. They are about twelve in number, somewhat thickened towards the outer extremities,

316 THE VOYAGE OF H.M.S. CHALLENGER.

which in adult shells do not reach the outer margin of the valves. Between the outer
ends _very short intervening ones are frequently met with, varying in number and
length.

Length IG mm., height 18, diameter 4^.

Habitat. — Stations 33 and 56, off Bermuda, in 435 and 1075 fathoms; Station 24,
off Culebra Island, in 390 fathoms, and off St. Thomas (depth not stated).

This species is without difficulty separable from Amussium liicidum by its different
sculpture, stronger substance, thicker internal lirge, and different form of the auricles.
The left valve is rather like that of the above-named species in respect of sculpture, but
is less glossy and more strongly concentrically ridged.

Amitssium meridionale, n. sp. (PI. XXIV. figs. 1-1 a).

Amussinm lucidmn, var. striata, Jeffreys, Proc. Zool. Soc. LobcI., 1879, p. 562.

Testa fragilissima, paulo insequivalvis, iridescens, pellucida, utrinque anguste hiaus.
Valva dextra liris filiformibus numerosis radiantibus, iucrementique lineis concentricis
ornata, sinistra magis opaca concentrice lirata, liris tenuissimis, complanatis, sensim
aecrescentibus. Auriculae subsequales, anticis interdum paulo majoribus. Pagina in-
terna nitida, ii-idescens, liris tenuissimis undenis instructa, in valva dextra radiatim
striata, striis cum liris externis congruentibus.

Var. ; Testa liris internis duodenis muuita, valva dextra extus cancellata.

This species is slightly oblique, excessively thin, a little inequivalve, pellucid white,
and narrowly gaping above on both sides. The right or deeper valve is more glossy
than the left, and sculptured with numerous very slender radiating lirae and concentric
waves and striae of growth. The other valve is ornamented with close-set very fine
concentric shallow grooves and depressed ridges. The former under the microscoj)e
exhibit a very minute reticulation, each parallel zone of this fine net-work being
connected with the one above and below by elongate meshes passing over the inter-
vening ridges. The auricles are small, at times denticulated above, slightly unequal,
the anterior being rather larger than the posterior, or this proportion may be reversed.
The beaks are moderately acute, the sides meeting at an angle of about 115 degrees.
The valves are glossy, somewhat iridescent within, and strengthened with eleven
fine lirae, the longest of which extends about two-thirds across the interior. The
right valve is also very finely striated, the striae corresponding to the slender lirae
of the outer surface.

Length 14 mm., height 14, diameter 4.

Habitat. — Station 158, in the Southern Ocean, south of Australia, at a depth of

REPORT ON THE LAMELLIBRANCHIATA. 317

1800 fathoms. Also Station 14G, Southern Ocean, east of j\Iarion Island, in 1375
fathoms. Also Station 302, west of Patagonia, in 1450 fathoms.

The young of Amiissium dalli must approach very closely to this species. It may,
however, be distinguished on account of the more acute umbonal angles and the different
character of the surface structure of the left valve.

The specimens fx"om Station 302 present one or two differences from those found at
the two other localities. The right or deep valve has some of the concentric lines of
growth elevated into slender Krse, which, crossing those radiating from the beak, produce
a distinctly cancellated surface. Besides this, the valves are strengthened with twelve
instead of eleven radiating lii-se. However, taking into consideration the exact
similarity of the microscopic sculpture of the left valve, I believe it advisable to
consider this form merely as a variety. It is most surprising to me that this species
could for an instant be considered as a variety of Amussium lucidum. Any one
holding such a view certainly must either be wanting in perceptive power or his
ideas respecting what are usually regarded as species be very peculiar. If any two
species of this genus are to be easily distinguished, those in question are they.
Amussium meridionale is larger, gapes on both sides, has both valves differently
sculptured, a shorter hinge-line, and the posterior auricle in the left valve is differently
sculptured. In specimens from a depth of 1000 fathoms, off the Azores, identified by
the late Dr. Gwyn Jeffreys as his Amussium lucidum, this ear has two or three radiating
ridges crossed by strong lines of growth, the former being wanting in Amussium
meridionale and the latter much finer. The Azorean examples also differ in being quite
closed at the sides.

Amussium lucidum, (.Jeffreys) (PI. XXIV. figs. 2-2c).

Pleuronectia lucida, JefiEreys, in Wyville Thomson, Depths of the Sea, p. 464, figs. 78, a, h.
Amussium lucidum, Jeffreys, Ann. and Mag. Nat. Hist., 1876, vol. xviii. p. 425.
Amussium lucidum, Jeffreys, Proc. ZooL Soc. Lond., 1879, p. 562.

Habitat. — Station 73, west of Azores, in 1000 fathoms; Station 78, off San Miguel,
xlzores, also in 1000 fathoms; Station 120, off" Pernambuco, Brazil, at a depth of 675
fathoms.

The Azorean specimens appear to differ in one respect from those originally described
by Jeffreys. The latter are said to have only nine internal supporting lirse, the figure,
however, in Thomson's book giving ten. In two valves in the British Museum I find
eleven, and in the Challenger examples usually fourteen, one or two of them occasionally
being only partially developed towards the outer margin.

318 THE VOYAGE OF H.M.S. CHALLENGER.

Family Osteeid.e.

Ostrea, Linne.
Ostrea imbricata, Lamarck.

Ostrea imbricata, (Lamarck) Sowerby, Conch. Icon., vol. xviii. pi. xvii. figs. 3G, a, h.
Habitat- — Station 188, south of New Guinea, in 28 fathoms ; green mud.

A single small specimen obtained at the above locality agrees with this species as
determined by Sowerby, examples of which from China and Japan may be seen in the
British Museum.

Besides this shell, another of immature growth, and belonging to a distinct species,
was dredged at Station 162, ofi" East Moneoeur Island, Bass Strait, in 38 fathoms; and
four young odd valves, respectively from Fayal, Bermuda, the Philippines, and Tongatabu,
none of which are safely identifiable, were also secured.

Family A N o M 1 1 D ^.

Anotnia, Linne.
Anomia ephippium, Linne, var.

Anomia epliippium, Linne, Syst. Nat., ed. 12, p. 1150.

Anomia ephippiuni, Forbes and Hanley, Brit. Moll., vol. ii. p. 325, pi. Iv. figs. 2, 3, 5, 7, and

PI. T. fig. 2.
Anomia epMppium., Jeffreys, Brit. Concli., vol. ii. p. 30, pi. i. fig. 4, vol. v. p. 165, pi. xx. fig. 1.
Anomia epMppium, Jeffreys, Proc. Zool. Soc. Lend., 1879, p. 554.

Habitat. — Station 122, off Pernambuco, Brazil, in 350 fathoms ; and off Nightingale
Island, Tristan da Cunha, in 100 to 150 fathoms.

A few small valves from these localities apparently belong to this well-known
European form. It has not, I believe, been previously obtained so far south.

Anomia laqueata, Eeeve, var. (?).

Anomia laqueata, Eeeve, Conch. Icon., vol. xi. pi. iv. figs. 18, a, h.
Anomia laqueata, Schrenk, Eeise Amur-Lande, vol. ii. p. 474.
Anomia laqueata, Dunker, Index MoU. Japon., p. 248.

Habitat. — Station 233a, off Kobe, Japan, in 50 fathoms.

The locality of this species was unknown to Eeeve, and was first assigned to it by
Schrenk. The Challenger specimens are smaller than the type, and do not exhibit the
radiating ridging depicted in Reeve's figure. They possibly are merely a smooth variety,
however, for the species of this genus, as in Ostrea, Spondylus, and some other genera,
are excessively variable and very difficult to determine.

APPENDIX.

Since .the foregoing Eeport passed through the press a few additional species which
had previously been overlooked have been transmitted to me for examination. They are
all from great depths in the North Pacific Ocean, and, as might be expected, appear to be
new to science. They do not, however, present any very remarkable features, but it is
very interesting to note that four of the five species are represented in the Atlantic by
forms which are all but identical.

NecBra murrayi, n. sp.

Testa elongata, gracilis, postice rostrata, insequivalvis, alba, tenuis, liris conccntricis
tenuibus subdistantibus postice ad carinam obliquam filiformem obsoletis iustructa.
Margo dorsi anticus leviter arcuatus, vix declivis, posticus elongatior, oblique concavus.
Margo inferior in medio parum excurvus, infra rostrum baud profunde sinuatus.
Rostrum angustum, ad extremitatem curvatum, supra carinam incrementi lineis striatum
lirisque paucis radiantibus inconspicuis ornatum. Cardo edentulus. Ligamentum
parvum, postice inclinatum.

This is a very slender species, of thin texture, narrowly rostrate behind, and inequi-
valve, the right valve being a little smaller than the left. It is white, with a dull
surface, and sculptured with very slender thread-like lirse which are
further apart upon the central portion of the valves than towards the
lower margin, and become obsolete or mere strise at the oblique keel,
which bisects the rostrate end. The rostrum itself is rather slender, ^y^^o murmyi, n. sp.
slightly up-turned, curved at the extremity, and sculptured with fine
lines of growth and a few very feeble radiating raised lines above the obhque keel. The
umbones are small, slightly in front of the centre, and posteriorly inclined. The
hinge is altogether toothless, and the ligament is small and directed obliquely towards
the hinder side. The interior of the valves is glossy, and, owing to their thinness,
exhibits the external sculpture.

Length 6 mm., height 2^, diameter 2.

Habitat.— Station 244, Mid North Pacific Ocean, in 2900 fathoms.

320 THE VOYAGE OF H.M.S. CHALLENGER.

This very delicate little species is readily separable from any of the species previously
described in this Keport by the fine and rather remote concentric lirse. It belongs to
Section M of the genus (see p. 38), characterised by a toothless hinge, concentric sculpture,
and a small posteriorly inclined ligament.

Callocardia (f) pacifica, n. sp. {ride p. 156).

A second specimen of this species, from the same locality, has fortunately been
preserved, having exactly the form of that previously described. The hinge in the right
valve is quite of the same character as that of Callocardia adamsii, consisting of a long
irregular tooth beneath and posterior to the beak, and a much shorter erect tooth in
front, separated from the posterior by a smaU notch, or, in other words, the hinge might
be said to consist of one elongate irregular tooth subdivided towards the anterior end by
a small notch.

Leda prolata, n. sp.

Testa parva, sequilateralis, antice acute rotundata, postice breviter rostrata, nitida,

albida, incrementi striis sculpta. Margo dorsi utrinque subrectilinearis, leviter

obliquus, ventralis curvatus, postice ad rostrum baud profunde sinuatus. Umbones
ad apicem obtusi, paulo prominentes.

Length 5 mm., height 3^, diameter If.

Habitat.— Station 256, July 21, 1875; lat. 30° 22' N., long. 154° 56' W.; depth,
2950 fathoms ; bottom, red clay ; Mid North Pacific Ocean, north of
the Sandwich Islands.

This species very closely resembles Leda rectidorsata of Seguenza,
Leda prolata, n-sp. ^^^ "^^s dredged in deeper water than any other Lamellibranch
obtained during the Expedition. There being but a single specimen,
I have not ventured to open the valves in order to examine the hinge.

Yoldia lioylei, n. sp.

Testa parva, tenuis, ovata, insequilateralis, nitida, albida vel dilutissime olivacea,
striis incrementi tenuissimis sculpta. Umbones parvi, parum pro-
minentes, paulo excentrici. Linea cardinis gracibs, dentibus erectis sex
utrinque instructa.

Toldia hoyki, n. sp.

This species, judging from the two specimens at hand, is small, ovate,
highly glossy, a little inequilateral, and sculptured with very fine lines of growth. The
valves are very thin, almost equally rounded at the ends, but the curve on the longer

REPORT ON THE LAMELLIBRANCHIATA. 321

side is rather higher up than iu front. Tlie (hn-sal margin is straightish on each side the
beaks, which are small, slightly prominent, and rather excentric. Tlie hinge is slight,
and armed with about six teeth on each side the small ligament-pit. The interior is
bluish-white.

Length 3f mm., height 2^, diameter 1^.

Habitat. — Station 244, Mid North Pacific Ocean, in 2900 fathoms.

Leda Jeffrey si, Hidalgo, is the Atlantie analogue of this species.

Area {Barbatia?) imitata, n. sp.

Testa forma habituque Arcce frielei simillima, agquivalvis, oblique rotuudata, sub-
globosa, inseqnilateralis, albida, epidermide tenui pilosa pallide fuscescente induta. Valv£e
tenues, liris tenuibus radiantibus aliisque conceutricis paulo minus conspicuis can-
cellatse.

Length 3f mm., height 3, diameter 2 J. '

Var. ; Testa magis elongata.

Length 4^ mm., height 3^, diameter 2g.

Habitat. — Station 244, Mid North Pacific Ocean, in 2900 fathoms.

This interesting form belongs to a small group of species which bear a strong family
likeness to one another, namelj^, Area pectuncndoides, Area frielei,
Area incBquiscidpta, Area cidehrensis, and a few others.

Area imitata differs from specimens of Area peetuneidoides of
similar size in being more coarsely clathrate and in having the
valves equal, whereas, in the latter species, the right is smaller
than the left. Area culebrensis is a more elongated shell than ' "" "'^ lo) »«> a «, n. sj..
that under consideration, Area inoequiseidpta differs in having the
valves differently sculptured and of unequal size, and Area frielei
has rather finer sculpture and is somewhat different in outline.
The distinctions above mentioned are but slight, and based upon
very limited material, and, without comparison of the specimens,

•; ... . , . Arca\BaTljatia)miiiata(\a.T.Y

it is impossible to discriminate the different species. I have

already recorded (p. 3) the existence of two all but identical species of the same genus
occurring at the above locality and at a great depth in the Atlantic. Here again is an
instance in which the genus Area has almost exactly simdar representatives in the two
oceans, at enormous depths.

(ZOOL. CUAU.. E.\P. PART .XXXV. — ISS-".) J[lll 4 1

APPENDIX 11.

Since receiving the specimens described in the preceding Appendix, a few others
have been forwarded to me for examination. They consist of a Malletia, a Leda, a
Glomus, one Limopsis, two species of Area, and a Spondylus. They are of special
interest in coming frorn Stations from which Lamellibranchs have not previously been
reported, and all, excepting the Limopsis and the Arcce, are new and very interesting
species.

Malletia dunkeri, n. sp.

Testa parva, intequilateralis, uitidissima, iridescens, semipellucida, tenuissima, vix
concentrice striata, oblonga, antice angustata, acute rotundata, postice latior, sub-
quadrate arcuata. Margo dorsi anticus brevis, declivis, vix arcuatus, posticus longior,
rectiusculus, horizontalis ; margo inferior late curvatus. Umbones parvi, albidi, aliquanto
obtusi, circa in ^ longitudinis coUocati. Dentes cardinis ad sedecim in utraque valva,
hand acuti. Ligameutum externum augustum, lineare.

This species is considerably inequilateral, excessively thin, semitransparent, highly
glossy, iridescent, and exhibits but very faint lines of growth. It is longer than high,
narrower and more sharply rounded in front than behind. The front
portion of the dorsal margin is short, very sloping, and a little
excurved. The posterior side is much longer, horizontal, and also ^^
only very little arcuate. The ventral outline is widely curved, and ifaiutia^i^iTn sp
ascends obliquely behind rather further than in front, so that the
posterior extremity is higher up than the anterior. The beaks are rather obtuse, very
little prominent, opaque white, and situated at less than a third the length of the shell
from the anterior end. The hinge consists of about sixteen squarish-topped teeth in each
valve, of which about ten are behind the umbones and the rest in front, and, owing to
the thinness and transparency of the shell, are clearly visible when the valves are closed.
The ligament is very slender, and, commencing between the beaks, extends a short
distance behind them.

Length 5 mm., height 3i, diameter 2;^.

324 THE VOYAGE OF H.M.S. CHALLENGER.

Hahiiat. — Station 237, off the south-east of Nipou, Japan, in 1875 fathoms.

This is quite distinct from all the known species of Malletia, and is the only one at
present known from Japanese Seas. I have named it after the late Dr. W. Dunker,
author of several papers and valuable works on the Mollusca of Japan.

Leda ultima, n. sp.

Testa minuta, ovato-subtriangularis, convexa, antice rotundata, postice angustata,
subrostrata, ilavescens, parum nitida, liris tenuibus concentricis confertis regularibus
sculpta. Margo dorsi utrinque ajqualiter deelivis, antice vix curvatus, postice rectus.
Margo inferior late arcuatus, extremitatem posticam versus ad termiuum impressionis
lataj ab umboue radiantis incurvatus. Umbones albi, Iseves, centrales, involuti, haud
acuti. Liuea cardinalis crassa, dentibus cii'citer sex utrinque iustructa.

This little species is rather thick in texture, considerably convex, ovate but

narrowed at the hinder end into a short rostrate extremity. It is white, clothed with

pale straw-coloured epidermis except at the umbones, which consequently

appear white, and are smooth, central, slightly prominent, rather obtuse

and incurved at the tip. The valves are marked with a distinct broad

, , „. radiating depression down the posterior side, and sculptured with

LccUt ultima, n. sp. o -^ ^ ' >-

numerous regular fine close-set concentric lirje which become more slender
at the sides. The dorsal line is considerably sloping on both sides, the least excurved
in front, straight at first behind the beaks, then down-curving to the sharpish rostrate
extremity. The ventral margin is well curved in front and along the middle portion
of the valves, but distinctly sinuate at the termination of the oblique impression. The
hinge-plate is very strong and broad for so small a species, and furnished with six
or seven teeth on each side the small central triangular ligamental pit. The interior is
glossy, and exhibits distinct deep muscular scars.

Length 2|- mm., height 2, diameter 1:^.

Habitat.— ^l^tion 5, February 21, 1873; hit. 24° 20' N., long. 24° 28' W.; south-
west of the Canary Islands ; depth, 2740 fathoms ; bottom, red clay.

Leda messaneiisis is more sharply beaked behind than this species, more finely
sculptured, more narrowly rounded in front, and has a less distinct oblique impression
down the posterior side. Leda semen is about the same size but more elongate,
has finer strise and a fainter depression.

Leda confinis is narrower, smoother, less equilateral, &c.

This little species, which is of thickish substance for a shell living in such deep
water, was obtained at a depth of more than 1000 fathoms in excess of that reached
by any other Leda obtained bv the Challenger.

REPORT ON THE LAMELLIBRANCHIATA. 325

Glomus japonicus, n. sp.

Testa parva, tenuis, rotiuulato-ovata, subsequilateralis, parum nitida, epitlermide
tenui flavescente, coucentrice teuuiter striata, iuduta. Margo dorsi anticus prirao
leviter arcuatus, dein oblique suljrecte declivis, ventralis late regulariterque arcuatus.
Umbones parvi, paulo prominentes, albi, fere mediani; Ligamentum cardinale obliquum,
parvum, postice inclinatum. Dentes circiter- septem ante umbones conici, acuti, pos-
teriores ad tredecem magis obliqui, minores. Pagina interna nitida, pallida cseruleo-albida.

This species is longer than high, roundish ovate, rather more pointed in front than
behind. It is moderately convex, very thiu and fragile, the slightest inequilateral, the
anterior end being a trifle longer than the posterior. It is clothed
with a thin pale yellowish epidermis, is glossy only at the umbones,
and marked with very fine incremental stria3. The beaks are small,
white, the least raised above the dorsal line, and situated the slightest
behind the centre. The front dorsal maroin is shortly curved at ^,
first, then descends obliquely in a straightish line to the anterior
extremity. The posterior margin descends rather more obliquely from the beaks in a
gentle curve. The hinge-plate is feeble and bears about seven conical teeth in front of
the centre and twelve or fourteen rather smaller and more oblique ones on the hinder
side. The ligament is small, and inclines obliquely towards the posterior side from the
tip of umljones. The interior is glossy, and of a pale bluish tint.

Length 5 mm., height 4|, diameter 2\.

Habitat. — Station 237, off the south-east of Nipon, Japan, in 1875 fathoms.

Until the discovery of this species, the genus Glomus has only been known as
an Atlantic type. This is quite distinct from all the other .species,- being larger and
different in form and dentition.

Limopsis cristata, Jeffreys, var.

Limopsis cristata, Jeffreys, Ann. and Mag. Ifat. Hist., 1876, vol. xviii. p. 4.34.
Limopsis cristata, Jeffreys, Proc. Zool. Soo. Lond., 1879, p. 58.5, pi. xlvi. fig, 8.

Habitat.— ^t-Aiion 5, February 21, 1873; lat. 24° 20' N., long. 24° 28' W. ; south-
west of the Canary Islands ; depth, 2740 fathoms ; bottom,
red clay.

iw^m I

The single perfect specimen and a few odd dead valves
from the above locality do not correspond exactly with the umojms cnsiata, iim^^. - ,-r/w,
typical examples oi this species with which 1 have com-
pared them. They are rather less oblique in growth, have the anterior side, or that

326 THE VOYAGE OF H.M.S. CHALLENGER.

towards which the umboncs incline, somewhat straighter, the crenulation or dentition
within the margin of the valves is less developed, and the hinge-teeth appear to be
fewer. The character of the external sculpture, however, is exactly similar, and possibly
were a larger series of specimens at hand, the above slight differences would prove to be
inconstant.

Area (Bai'batia) pteroessa {vide p. 262).

Habitat.— S>tiition 237, June 17, 1875; lat 34° 37' N., long. 140' 32' E.; depth,
1875 fathoms; bottom, blue mud (off the south-east coast of Nipon, Japan). Also
Station 16, March 7, 1873; lat. 20° 39' N., long. 50° 33' W.; depth, 2435 fathoms;
bottom, Globigerina ooze (Mid North Atlantic, east of the West Indies).

It is interesting that other specimens of this species have come to hand which were
obtained from the Pacific, being confirmatory of its existence in that and the Atlantic
Oceans.

Ai-ca [Scapharca) incBquisculpta {vide p. 267).

Habitat. — Station 5, south-west of the Canary Islands, in 2740 fathoms.

A single half-grown example in perfect condition from the above locality shows that
this species is, as I suspected, inequivalve, and therefore belongs to the section
Scapharca. It is clothed with a thin pale brownish epidermis, which, under a strong
lens, presents a finely hairy aspect, the short hairs arising from the points of intersection
of the slender concentric and radiating lirse. It is interesting to find this species also
occurring on the eastern side of the Atlantic, more than 2000 miles from the only other
locality whence at present it has been obtained.

Spondylus ostr-eoides, n. sp.

Testa parva, altior quam longa, alba, infsquivalvis. Valva superior ii-regulariter
planiuscula, incrementi lineis concentricis lamellatis confertis undulatis sculpta. Valvae
inferior — ? (tubulis vermium, &c., obtecta). Pagina interna alba, nitida, cicatrice
musculari subrotundata distincta notata. Margo valvse supei'ioris denticulis minutis
remotis intus instructus, valvse inferioris fossis vel puncturis congruentibus sculptus.

The single specimen obtained is of small size, and consequently may not be adult.
It is of the same general form as many other species of the genus, but is remarkable

EEPORT ON THE LAMELLIBRANCHIATA. 827

in being concentrically sculptured and lacking the radiating ridges, usually spine-bearing,
which, so far as I am aware, are present ui)on the upper or free valve of every known
species. This absence of radiating sculpture, and the lamellated character of the
concentric lines of growth, gives this species very much the appearance of a small
oyster, which suggested the name Spondylus ostreoides. The inner margin of the valves
of most species of this genus are fluted, a style of sculpture occasioned by
the external ribbing. In the present form this generic character is main-
tained in a modified form, the upper valve having nearly all round,
somewhat remote elongate tubercles which fit into minute pits or
punctures in the other valve.

Length 11 mm., height 14, diameter 6.

Habitat— Station 170, July 14, 1874 ; lat. 29° 55' S.,long. 178° 14' E.;
depth, 520 fathoms; bottom, volcanic mud (north of the Kennedec '^

Spondylus ostreoides.
Islands). l, exterior; 2, inter-

Most of the known species of Spondylus (with the exception of a few
brought up on telegraph cables) have hitherto been obtained in comparatively shallow
water. The absence of colour in the present form, and its depauperated condition, is
probably the result of existing in deeper and colder water than usual, and fine handsome
species are not to be expected from such localities. A fact worth mentioning in this
place is the presence, upon the upper valve, of a species of Polyzoa, which my colleague
]\Ir. Quelch pronounces without doubt to be Crihrilina radiata (Moll.), a form found in
shallow water on the British coast.

INDEX.

Note. — Names of Genera and Species obtained during the Expedition are printed in roman type,
Synonyms and other Species incidentally referred to in italics.

Abr.i,

longicallis, Sars,
Alicia aiujustata, Angas,

elegantula, Angas,
Amussium, ....

caducum, n. sp., .

cancellatum, n. sp.,

dalli, n. sp., .

jefireysii, n. sp.,

lacidum, Jeffreys, .

meridionale, n. sp.,

obliquum, n. sp., .

pleuronectes (Linne),

propinquum, n. sp.,

scitulum, n. S])., .

squamigerum, n. sp.,

torresi, n. sp.,

watsoni, n. sp.,
Amphidesma amabilis, .

caslanea,

obliqua,

variegata, Lamarck,
Anatina, ....

amphora Reeve, .

brevis, ....

crassa, Stutchbnry,

cumingii, Valenciennes,

elliptica, King <£; Broderij),

flexnosa. Reeve,

paiidoriformis, Stutchbury,

pris7natka, Sowerby,

siphonata, Reeve, .

ANATlNIDiE, ....
ANATININa:, ....

Anomia, ....

AN0M1ID.E, ....

Anomia epbippium (Linn4), var.,
laqueata, Eccve, var. (?),
(ZOOL. CHALL. EXP.— PART XXXV

Plate

Figure

Page

( 3,4,6,89,90

... j

106

88
68
68

297, 308

XXIII.

1-lc

20,

309, 312

XXIII.

8-8c

8, 9, 315

XXII.

7-7c

308, 317

XXII.

2-20

21, 310

XXIV.

9, 10,11,315
316, 317

XXIV.

i-i« j

13,
317

23, 316

XXIII.

6-6a

8, 313

, 20, 308

XXIII.

7-7&

10, 314

XXIII.

4-4ft

19, 312

XXIII.

5-5a

8, 312

XXIII.

3-3i

311,312

XXII.

8-8c

21, 309
83
79
84
84
76
76
64
65
76

13, 76
76
64
76

21, 76

318

, 12, 318
22, 318

Plate Figure

5-56

Antigo.va lamellaris, Schumacher, ...
Akca,

(Acar) congenita, n. sp., xvir.

(Acar) domingensis, Lamarek, ...

angicostata, Keeve,

aurita, Brocchi,

(Barbatia)corpulenta,7!. sp., xvii.

(Barbatia) fasciata, Reeve,
(Barbatia)fusca, BrMjitiirc,
(Barbatia) imitata, ?i. s/j.,
(Barbatia) lima, Reeve, .

(Barbatia) pteroessa, ?i. sp., xvii. 4-46

(Barbatia) radula, A. Adams, ...
(Barbatia) sculptilis, Reeve,
cftakanthum, Keeve,
clathrata. Reeve, .
cumingii, Dunker,
cuneata, Keeve,
domingensi.s, Lamarck,
fasciciUi, Reeve,
friclci, .

fusca, Bruguiure, .
gubemacxdum. Reeve,
imbricata, BruguUre,
kratissi, Philippi, .
lima, Reeve, .
linter, Jonas,
luzoiiica. Reeve,

(Macrodon) dalli, n. sp., xvii. 10-106
naviculaiis, Bruguiire,
noEB, Linni, .
parva, Sowerby, .
pectinata, Gmelin, .
peclunculoidcs, Scacchi,
radiata, Reeve,
radula, A. Adams,
(Scapharca) angicostata

Reeve,
(Scapharca) clathrata, Reeve,

Page

121

... 4,6,258,323

6-6a 20, 264

8, 10, 265

265

257

5, 16, 19, 20

21, 23, 263

15, 260

16, 260
321

17, 21, 260
4, 8, 9, 22
262, 326

14, 260

20, 262

266, 267

266

259

265

260

267, 268, 321

260

266

4,11,18,259

259

260

259

266

22, 269

17, 259
8, 258

261
250
267, 268, 321
266
260

■1885.)

21, 263
18, 20, 266
Mm 42

330

THE VOYAGE OF H.M.S. CHALLENGEK.

Arca — continued.

(Scapharca ?) consociata,

n. sp

(Scapharca?) culebrensis,

n. sp., .
(Scapliarca) g\il)eniacu

luin, Rccre,
(Scapharca) inanui- |

sculpta, }i. sp., . \
sculptilis, Reeve, .
semilorla, Lamarck,
stellaia, Brugvii&re,
subquadrangula, Dunker,
tetragona, Poli,
(Trisis) semitorta, Zam- )
arck, ■ ■ ■ \
umhonala, Lamarck,

Arcid^

ARCINiE

ARTEMrs {dementia) papyracea,
lamhatii,

lenticularis, Sowerby, .
lirata, Sowerb}-, .
scabra, Philippi, ■
sculpta, Hanley, .
vancgata, Reeve, .
Arthemis lambata, Gould,
ASTARTE, . • ■ •

loiigiroslra, d'Orbiguy, .
limnlata, Conrad,
macandrewi. Smith,
■mactracea, Linsley,
magellanica,
magellanica. Smith,
pfeiffcrl, Philippi, .
triangularis,
AsTARTiDa;, . • • ■

ASTARTIN^

AVICULA, . . . •

ala-pcrdids, Reeve,
chamoides, Reeve, .
flahellum. Reeve, .
hurritia, Dunker, .
macroptera, Lamarck, .
(Meleagrina) nmricata,

Reeve,
(Meleagrina), smarag.

dina. Reeve, .
(Meleagrina) squanui

losa, Lamarck,
murieata, Reeve, .
smaragdina. Reeve,
squamulosa, Lamarck,
AVICULIDiE,
AxiyiA holosericus, .
AXINUS,

angxdatus,
croulineims, .
flexuosus,
incrassatus, Jeffreys,

Plate
XVII.

XVII.

Figure Page

7_7„ 19, 266

9-96 8, 268, 321

8-8c

I 8,
132

Plate Figure

1-lu

15, 206
;67, 321,

262
268
250
259

9, 259

18, 268

259

248

258

154

151

152

153

152

151

209

220

10, 209
220

i
13, 209, 210
220
209
209
209
284, 305
285

285

285
285

17, 284

18, 284
17, 285

S, 284

284
285
284
284
251
187
187, 188
193
192
193

AzOK (Macha) scheepmakeri
Dunker,

ohlongus, Dunker, .

sotidus, Dunker, .
Bar BAT! J,

fasciata,
CaLUSTA muUistriata, .
Callocaudia,

(?) adamsii, n. sp.,

(?) atlantica, n. sp. ,
guttata, A. Adams,
(?) pacifica, n. sp.,

CARDIIDiE,
CARDIIN'iE,

Cardiomta, .

Cardita,

astartoides. Martens,
beddomei, n. sp., .
bimaculata, Deshayes,
borealis, Conrad, .

calyculata, Linni,

canaliculata. Reeve,
cardioides. Reeve, .
concamerata, .
crenulata, Deshayes,
cumiHgii, Deshayes,
dilecta, n. sp.,
essingtoncnsis, Deshayes
excavata, Deshayes,
insignis, n. s?).,
nmricata, Sowerby,
pica. Reeve, .

(Thecalia) concamerata

[diemriilz),

umbilicata, Deshayes,

veluiina, Smith, .

Carditella, .

angasi, n. sp.,

capensis, n. sp.,

exulata, n. sp.,

inf ans, n. sp. ,

pallida. Smith,

torresi, n. sp.,

CARDITINiE,

Cardium,
Cardium,

(Acanthocardium)

pillosum, Poli
(Acanthocardium)

sura, Ecdficld,
(Acanthocardium)

ieuse, Issel,
adamsii. Reeve,
asiaticum..

Page
79

XV.

8-Si.

-96

2-2c
5-5a

XV.
XV.

XV.
XV,

seto

Suez

264

260

13*

4, 155, 156

^ 3, 25, 155,

''"'* ■( 157, 320

\ 3, 9, 10, 157

263

156

\ 3, 22, 156.

' ( 157, 263, 320

158

210, 214

13, 212, 213

14, 211

212

I 4,10,14,210

I 215

21, 211

211

214, 215

211

14, 213
210

15, 210
19, 214

210
210

14, 213

12, 214

210
212
215

15, 217
12, 216, 217

12, 215
19, 218
216
19, 217, 218
210
158
203

9, 10, 158

4-4a

3-3'-

9-9('

7-7t;

6-6«

10-1 Of

8-8rt

1-ib

158
16, 158

164
159

REPORT ON THE LAMELLIBRANCHIATA.

331

Cardium — conlinued.

nspcrsum, Sowerby,

asperum, Riiiner, .

aitstralc, Sowerby,

hiancjulaluin,

(BucarJium) australe, Sowerby,

(Bucai'iliuni) inirabilf, i

Dcsluii/es, . . \
(Bucardium) multispino

sum, Sowerby,
(Bucardium)pulclienum,

Gray, .
(Bucardium) tenuicosta-

turn, Lamarck,
bullalum,

fornicaluiii, Sowerby,
(Fulvia) bullatum,
(Fragum) fornicatuui,

Sowerby,
(Fragum)imbricatum,<S'o)»<;?'J2/,
(Fraguni) medium, Linni,
(Fragum) torresi, n. sp., \
glabratum, Romer,
hiulcum, Reeve,
imhricatum, Sowerby
(Lwvicardium) norvegi- |

cum, SpcngUr, var,
lievigatum. Reeve, .
latum. Born,
medium, Linne,
mirabile, Deshayes,
muUispiiwsum, Sowerby,
norvegicum, Speiigler, .
rwvce zclandieB, Desbayes,
pallidum, Rbmer, .
papillosum, Poli, .
(Papyridea) bullatum, £t)!»i^,
(Papyridea) ringiculum,
(Papyridea) semisulca-

tum, G-ray,
(Papyridea) transversale,

Dcsluiyes,
petitianum, d'Orbigny, .
planicostatum,
pukhcllum. Gray, .
pulchrum. Reeve, .
radialum, Romer, .
ringiculum, Sowerby, .
semisulcatum. Gray,
setosum, Redfield, .
soleniformc, Bruguiere, .
slrialulum, Sowerby,
suezicnsis, Issel,
tenuicostatum, Lamarck,
transversale, Deshayes, .

Chama,

brassica, Reeve,
carditisformis (?), Reeve, .
concavwrala, Chemnitz, .
fibula. Reeve,

Plate

^'iguro Page

Chama — continued.

Plate

Figure

Page

161, 162

gryphoides, Liiini,

9, 10, 171

161, 162

jukesii. Reeve,

17, 172

160

innJtlsquairwsa,

172

163

pectitmta.

224

16, 21, 160

pcllis-phoea;, Reeve,

172

1-lc 20, 159

spinosa, Jlroderip, .
sulphurea. Reeve, .

1.^., 173
18, 171

18, 19, 160

Chaw

IDM,

...

171

C//W

VE a-ustralis, .

131

14, 161

exalbida,
foliacea,

117

1-22

15, 21, 159

(Marcia) undulosa,
mcsodestna, .

132
131

... 158, 161, 162

retroversa, Deshayes,

122

164

striatissima, .

124

161

undulosa,

132

16, 164

Circe, ....

albida, .

141,

221, 222, 223
221

17, 164

arnica, n. sp.,

11.

2-2C

16, 145

11, 163

angasi, n. sp..

II.

4-4e

14, 148

4-4t 18, 164

arlemis, Deshayes,

142

163

australis, Sowerby,

18, 142

161, 162

bermudensis, n. sp..

II.

1-lA

8, 143

164

castrensis.

144, 221, 222

10, 163

cerina, .
cyrilli, .

221, 222
148

163

dispar, .

142, 221

158, 161

divaricata.

221, 222

163

fastigiata, (Sowerby),

17, 146

159

gibbia, {Lamarck),

18, 143

160

gordoni, n. sp..

II.

5-5c

16, 146, 147

163

hebrcca, .

138

161

hicroglyphica, Conrad,

146

159, 160

jucunda, n. sp..

II.

3-36

18, 22, 144

158

Icntiginosa,

...

221

12, 161

inelcalfei, Deshayes,

142

162

minima, {Montagu),

... 9

, 10, 141, 148

12, 162

obliquissima, n. sp.,
pacta, Romer,

II.

6-66

17, 149
142

3-36 9, 10, 162
162

picla, Lamarck,
scripta, {Linni), .

146, 147
14, 18, 141,
221, 222

163

sulcata. Gray,

16, 21, 142

161

sulcatina, Lamarck,

146

160

trimaculata, Lamarck,

146, 221, 222

159, 160

testudinalis, .

222

162

ligrina, Lamarck, .

146

162

undalina.

142

21, 158

Clausina croulinensis, Jeffreys

193

161

Clav

AGELLA, .

161

torresi, Ji. sp..

VII.

1-16

18, 28

4, 158

Clavagei,lin.e,

159, 160

Clementia, .

154

162

cumingii, Deshayes,

...

154

171

hyalina, Pfeifer, .

154

16, 171

morctonien.tis, Deshayes,

154

21, 172

papyiacca, {Gray),

18, 154

214

similis, Sowerby, .

154

172

slrangei, Deshayes,

...

154

J32

THE VOYAGE OF H.M.S. CHALLENGER.

Clemsstix— continued.

Plate

Figure

Page

Cytherea — continued.

Plate

Figure

Page

subquadrala, A. Adams,

154

costata, Chemnitz,

134

Cuil.ODON

diemenensis, .

... 133, 134, 136

dclicatulus, A. Adams, .

(Dione) philippinarum, H

anlcy.

... 16,

19, 23, 141

elongatus, Carpenter,

17, 62

disrupta, Sowerby,

135, 136

Coxus cancellatus, .

221

crythraea, Jonas, .

142

nmrinorcus, .

221

fastigiata, Sowerby,

146

CORBULA

gihhia, Lamarck, .

143

crassa. Hinds, var.,

18, 29, 30, 13

(Gomphiiui) moerchi. An,

;as, ...

132

macgillivrayi, n. sj).,

8-86

18, 30

grata, . . . .

134

modesta. Hinds, .

16, 20, 32

Jiebrcea, Lamarck, .

138, 139

monilis. Hinds,

17, 18, 34

innocetis, Sowerby,

136

operculata, Philippi,

interrupla, Lamarck,

179

philippi, n. sp.,

VII.

i-ih

8, 33

lilacina, Lamarck,

133, 134

scaplioides, Hinds,

VII.

3-36

18, 31, 32

mcndana:, Philippi,

141

sulcata.

30, 32, 33

minuta, Koch,

140

tuuicata, Hinds, .

: !

14,19,20,29
30, 32, 33

multiradiata, Sowerby,
inultistriata, Sowerby, .

130
134, 136

CoRBULIS^, ....

pectorali-s, Lamarck,

133

L'K.A.SSATELLA

219,

220, 222, 223

pellucida, Lamarck,

1.39

aurora, A. Adams and Angas,

14, 219, 220

phasianella, Deshayes, .

137

Jcingicola,

222

philippinarum, Hanley, .

141

parva, (C B. Adams), .

8, 220, 222

planatella, Lamarck,

136

guadaloupensis, d'Orbigny,

220, 221

plehcia, Hanley,

142

rhomboides, n. sp..

XVI.

l-lo

18, 19, 219

roseotincta, n. sp.,

137

torresi, n. sp.,

XVI.

2-2«

19, 223

rostrata, Koch,

137

Ckassatellidj;,

219

rutila, Sowerby, .

133

Cj^ ASS A Try. 4, ....

220

soligena.

139

CliENELLA

277

sophice, Angas,

138

decussata, Montagu,

278

varians, Hanley,

139

marionensis, ?i. sp..

XVI.

6-6,t

13, 277

Dacuydium

4, 6, 282

(Modiolaria) camingiana,

278

meridionale, n. sp..

XVII.

2-2a

13, 282

Ci:enellixjj, ....

277

occidentale, 71. sp..

XVII.

1-la

8, 282

Cryptodon, ....

(?) barbatus, (Seeve),

4, 6, 185, 187
8,190

vitreum, (Holler), .

5, 9, 10
282, 283

Viullulus, {Becve), .

20, 189

Da^

ILA

croulinensis, (Jeffreys), .

...\

7, 10, 193,
194, 195

plana, Hanley,

(?) umbonata, n. sp..

VI.

1-16

83
13, 82, 83

falklandicus, 71. sp.,

XIV.

3-3(1

24, 190, 191

varicgata.

flexuosus, (Montagu),

9, 192, 194

Descriptions of Species,

gouldii, Philippi, .

194

D/o

\B grata, Deshayes, .

133

iucrassatus, (Jeffreys), var. ,

8, 193

hehroM, .

138

Uizouicus, n. sp., .

XIV.

5-5(1

20, 192

lilacina.

133

marionensis, n. sp..

XIV.

6-6a

13, 194

mullistriaia, .

134

nioseleyi, n. sp., .

XIV.

2-2(1

12, 189

rostrata,

137

rufolineatus, n. sp.,

XIV.

i-ia

16, 191

rutila, .

133

sp., ....

7, 25, 194, 195

DiPLODONTA, .

... 1

74, 195, 200

watsoni, 11. sp..

XIV.

1-1(8

21, 188

amboinensis, n. sp..

XIV.

12-12a

20, 199

Cytherea, ....

132, 222, 247

apicalis, Philippi, .

10, 200

(Callista) cliione, Linni,

10, 132

conspicua, n. sp., .

XIV.

11-11<J 1

',18,19,198

(Callista) disrupta, Sowerhy,

4-4e

14, 135

corpulenta, n. sp..

XIV.

9-9(J

19, 196

(Callista) grata.

133

lamellata. Smith, .

173

(Callista) lilacina, Lamarck,

21, 133

rotundata.

200

(Callista)multistriata,So«>cr6)/, i.

5-5(^

15, 134

soalpta, n. sp..

XIV.

8-8(T

18, 196

(Callista) roseotincta, n. sp..

6-66

21, 136

sp.,

12, 14, 200

(Callista) rutila, Sowerhy,

14, 133

subglobosa, ?i. S2>.,

XIV.

W-Wa

17, 18, 197

(Caryatis) coxeni. Smith,

7-7c

18, 139

subgranulosa, n. sp..

XIV.

7-7a

21, 195

(Caryatis) hebriea, Lamarck,

21, 138

trigonula, Broun, .

200

(Caryatis) regularis, n. sp.,

8-86

18, 140

■ARICELLA,

177, 178

(Caryatis) rostrata, Kuch,

25, 137

t DONACID*;,

112

REPORT ON THE LAMELLIBRANCHIATA.

333

Plate

Figure

Page

Plate

Figure

Page

DONAX

99, 112

HiPPAGUS aculicostalm, Philippi,

165

aistanm, Montagu,

HuxLEYiA sulcata, A. Adams,

231

irus, Linne, .

112

Idas,

281, 282

iiitidus, Deshayes,

14, 18, 113

dalli, n. sp., .

XVI.

10-106

8, 281

nitida, Reeve,

112

Introbuction,

DOSINIA,

...

149

JSOCARDIA cor.

...

157

units, Philippi,

152

IsOCARDIIDJE,

154

cireinaria, Deshayes,

2-2i;

14, 150

Julia, .

269

deshayesii, A. Adaiiis, .

l-lc

18, 149, 150

exquisita, Oould,

22, 269

histrio, {Ginelin), var., .

17,18, 19,152

JULIID.E, .

269

juvcnis, Cheianitz,

150

Katelysia, .

117

tainarchii, Gray, .

121

Kellia, .

201, 204

lambata, [Gould), .

15, 151, 152

adamsi, (Angas),

14, 203

mira, 1I. sp., .

Z-Ze

19, 152

cardiformis, n. sp..

XI.

6-66

13, 202

scalaris, Menke,

150

cycladiforim.i, (Deshayes),

202

sculpta. Hanky,

18, 153

nuculina, Martens,

XI.

4-46

13, 201

suhrosea. Gray,

152

rotunda, (Desliayes), var.,

XI.

5-56

14,

202, 203

DosiNiiN^,

149

13, 201,

Dreissenin^,

271

suborbicularis, Montagu,

... j

203

Endopleura,

Kelliblla, ....

156

Eriphyla,

222

miliaris, . -

157

EllVILIA,

Kelliid^,

201

aiistralis, Angas,

Laxia lata, Sowerby,

235

bisculpta, Gou!d,

14, 2.3, 80

micaiis, Sowerby,

236

castanea, {Uontnga),

5,9,10,79,81

crassa, Sowerby,

237

incolor, Deshayes MSS.,

Lamellibkanchiata,

1, 2, 27

niteits, ....

Leda,

.:■ 1

4,6,231, 232

subeancellata, ?t. sp..

YI.

2-2b

8, 11, 80

242,323,324

sandwichensis, n. sp., .

XXV.

5-5/.

22, 81

acuminata, Jeffreys,

237

Erycina cycladiformis, Deshayes,

202

chuva, .

239

denticulata, Deshayes, .

204

confinis, n. sj)..

XIX.

5-5a

10,

233, 324

Imigicallis,

corbuloides, n. sp.,

XX.

1-1«

19, 239

nitens, Montagu, .

crassa, (Hinds),

14, 237

rotunda, Deshayes,

202

decipiens, n. sp., .

XIX.

3-3a

8, 232

Gaimardia trapcsina.

279

despecta, n. sp , .

XI.X.

8 -8a

8, 235

Gari intermedia.

ensicula, Angas, .

14, 239

Gastroch^ena,

excisa, (Philippi), .

9, 232

dubia, [PcnnaM), .

10, 28

hebes, «. sp.,

XIX.

7-7«

8, 234

lamellosa, Deshayes,

VII.

2-26

17, 28

inaudax, n. sp.,

XIX.

4-ia

8, 233

modiolina, Lamarck,

inopinata, n. s}>., .

XIX.

9-9a

15, 236

Gastroch^nin^, .

Jeffreys!, Hidalgo, .

, 25, 234

General remarks on the Collection,

(Junonia) rcctidorsata

237

Geogkaphical Distribution,

Seguenza,

Glomus, ....

4, 248, 323

lata, (Hinds),

19, 235

intequilateralis, n. sp., .

XXI.

3-3i

8, 249

lata, Jeffreys,

234

j.iponicus, n. sp., .

325

Icnticula, Moller, .

234

jctt'reysi, n. sp..

XXI.

1-16

8, 248

10, 233

nitens, Jeffreys,

25, 248, 249

messanensis, Seguenza,

237

, 324

simplex, n. sp..

XXI.

2-2*

8, 249

micans, A. Adams,

16, 236

sp..

8, 249

nea;riformis, n. sp..

XX.

2-2a

17, 240

Gomphina undulosa.

132

novffi-gnineeasis, n. sp..

XIX.

10-lOa

19, 237

GOULDIA,

221, 222, 223

prolata, n. sp..

woodcut.

320

aicstralis, Angas,

148

rauisayi, n. sp.

XX.

3-3a

15, 241

cerina, .

221, 222

rectidorsata, Seguenza,

237, 320

guadalmipcnsis.

220

semen, n. sp..

XIX.

2-2a

11,

231, 324

maclracea,

220

solidula, n. sp. ,

XIX.

6-6a

11, 233

paeifica, C. B. Adams, .

221

ultima, n. sp..

324

parva, C. B. Adams,

220, 221, 222

ventricosa, Hinds,

238, 240

^eifferi.

220

watsoni, n. sp..

XIX.

11-lla

17, 238

834

THE VOYAGE OF H.M.S. CHALLENGER.

Plate

Figure Page

Lepton, ....

203

adamsi, Angas,

203

Ll.MA,

4, 6, 287

.Tiif^nlata, Stnccrhy,

15, 289

basilanica, Adams and Reeve, ...

289

hullata,

291, 292

buUifera, Desliayos,

288

caribcca, d'Orbigny,

288, 289

(Ctenoides) teneia, Chemnit

■}

16, 290

dunkeri, n. sp,,

291

excavata, Fabricius,

290

fasciala, Sowerby (nee Linne

), ...

289

goliath, Sowerby, .

.. 5, 22, 24, 290

hians, Gmelin,

290

ya^oMica, (A. Adams), Sowerby, ...

291

japonica, Dunker, .

291

lata, n. sp., .

XXIV.

3-3a 5, 11, 20, 2S7

(Liinatula) bullata, Born,

14, 15, 292

(Limatula)roiifusa, n. sp

XXIV.

6^6a 7, 10, 11, 292

(Limatula)lamiiiirera, n. sp.,

XXIV.

7-7a 7, 8, 293

(Limatula) pygmcea, i
Fhilippi, . . )

12, 13, 292

(Limatula) sp.,

.. 11, 12, 24, 293

(Limatula) subovata, Jeffreys, ...

10, 292

(Limatula) torresiana, «. «p.,

XXIV.

-5» 17, 291

losc&jnbii, Sowerby,

...

5, 291

(Mantcllum) bians, Gmelin,

8, 290

(Mantellum) loscombii, i
Sowerby, . , (

.. 5, 10, 12, 291

multicostata, Sowerby, .

.. 5,9,15,16,288

oricntalis, Adams and Reeve

289

omto, Jeffreys(n<;c Searles
Wood), .

292

ovata, Searles Wood,

293

paucicost-ata, .

287

pygmasa, Philippi,

292

sarsii

294

scabra, ....

290

squamosa, Laviarcl;

I 5,10,21,287,
■• j 288, 289

strangci, (A. Adams), Sowerby, ...

292

subovata, Jeffreys, ,

292, 293

tahitensis, n. sp.,..

XXIV.

-4a. 23, 289

tenera, Chemnitz, .

290

ietrica, Gould,

288

zcalaiulica, Sowerby,

288

Limatula falklandica, A. Adams

...

292

LiMID*,

287

LiMOP.SIS, ....

.. 4, 6, 254, 323

abyssicola, A. Adams, .

258

aurita, (Brocchi), .

S 7, 9, 254,
(257,258

bassi, n. sp., .

XVIII.

6-6a 14, 256

brazieri, Angas,

15, 256

cancellata, (Reeve),

17, 19, 256

cristata, Jeffreys, van, .

325

cumingii, A. Adams,

257, 258

lata, n. sp., .

XVIII.

7-7a 15, 257

marioueusis, n. sp..

XVIII.

-26 13, 254

LiMOPSis — continued.

minuta, (ridlippi),

pelagica, n. sp., .

phiUppii, A. Adams,

straminea, n. sp., .

torresi, n. sp.,

woodwardi, A. Adams, .
LlOCONCHA, ....

picta, ....
List of Stations, with the
names of the Species obtain-
ed at each,
LiTHODOMUS, .

antillarum {Philippi),

appendiculatus, {Philippi).

barbatu.% Reeve, .

bisuleatus, d'Orbiguy, .

corriigatus, Philippi,

Inuigcr, (Dunker), Reeve,

malaccanus. Reeve,

niger, d'Orbigny, .

semigranatus. Reeve,
LiTHOPHAGA appejidiculata, .

malaccana, .

nigra, ....
LuciNA,

adainsii, d'Orbigny,

amcricana, C. B. Adams,

barbala. Reeve,

buliula. Reeve,

chemnitzii, Philippi,

(Codakia) congenita, «. sjtj.

(Codakia) fijiensis, n. sp.

(Codakia) hawaiiensis, n.sp., xill.

(Codakia) interrupta, Lamarck,

(Codakia) levukana, n. sp., xiil.

(Codakia) pecten, Lamarck,
(Codakia) jiisum. Reeve,
(Codakia) seniiuula, Gould,
(Codakia) sp. y« I'.,
(Codakia) tigerina, {Linn6),
columbella, Lamarck,
cristata, n. sp., . . XIII.
{Cyclas) cumingii, Adams & Angas,
dcntaia. Wood,

divaricata, Auct. {nonlAwa.), ...
divarieata, Linne, .
{Divaricella) anguU/era, Martens,

(Divaricena)irpex,n. sp., xiil.

churnea, Reeve,

flexuosa,

interrupta,

irpex, n. sp., .

lamellata, {Smith), . XIII.

(Lnripcs) desiderata, n. sp., xiii.

(Loripes 0 gordoni, k. sp., xili.

Plate

Figure

:.. 1

Page

7, 8, 10,257,

258

4, 11, 22,

XVIII.

3-3r,

254

256

XVIII.

5-5«

13, 254, 255

XVIII.

4-4a

17, 255

256

222, 223

147

XIII.
XIII.

7-25

276, 278

8, 276

278

276

278

17, 277

276

279

276

277

276

173, 175

173

177

190

189

177

17, 182

16, 184

22, 183

16, 179

6-6« ! 16. 181, 182,
/ 183

8,11,179
19, 181

19, 180

20. 184
8, 179

10, 173

17, 175
177, 178
177, 178

177

178

177

I 17, 176, 177,

7-7a
9-9«
8-8a

3-3a

4-4«

( 178

1-16
10-10(S
12-1 2a

178
192
179
177

24, 173
19, 185
16, 186

REPORT ON THE LAJVIELLTBRANCHIATA.

335

LuciNA — continued Plate Figure

(Loripes ?) jacksonicnsia, j ^^^^^ 11-116

n. sp., .
nnacandrcce, H. Adams
(Myrtca) seminula, GoulJ
obliqua, Reeve,
ornata, Reeve,
oniatissima, d'Orbigny,
parvula, Gould,
pecten, Lamarck, .
pismn. Reeve,
plicifera, A. Adams,
quadrala, Angas, .
quMdrisulcata, d'Orbigny,
ramsayi, n. sp., . . xiii. 2-26
reticulata, (Poll), .
seminula,

sempcriana, Issel, .
serrata, d'Orbigny,
scyclicllciisis, d'Orbigny,
strigilla, Stimpson,
tigerina,

LuCINIDiB,

lutkarun^, .
Ltonsia,

formosa, Jeffreys, . . vi. 3-36

Ltonsiella, .

gemma, Verrill,

grandis, n. sp.,

jeffreysii, n. sp.,

papyracea, )i. sp., .
Macha abbrcviattis,

scheepmakeri, Dunker,
Mackodon,

ilACTRA,

acbatina, Chemnitz,

angulifera, Deshayes,

antiquata, Spenglei',

decora, Deshayes, .

depressa, Eeeve,

eximia, Deshayes, .

incarnata, Deshayes,

incerta, n. sp., . . v. 7-7i;

isabelleana, d^Orbigny,

jacksonensis, n. sp., . v. 9-96

locvis, Chemnitz, .

luzonica, Deshayes,

(Mactrinula) depressa. Reeve, ...

(Mactrinula) plicataria, Liniie, ...

maculata, Chemnitz,

maculosa, Lamarck,

mera, Deshayes,

jiiictefs, (Conrad ?), Reeve,

ornata. Gray,

oua/MM, Reeve (? Lamarck),

plicataria, Linne, .

pusilla, A. Adams, . v 8-8c

reevei, Deshayes, .

roslralis, Deshayes,

XXV.

3-36

XXV.

1-16

XXV.

2-26

Page
14, 185, 187

177, 178

180

179, 180

177

177, 178

186

179

19, 181

191

182, 184

177, 178

14, 174

179

181

177, 178

178

177

179

173

7,72

4, 6, 73, 75

165, 166

166

12, 74

11, 73, 74

13, 73, 75

269

22, 59, 60

19, 60

21, 58

22, 59
25, 58
14, 62

14, 57

17,57

204

14, 60, 62

59
56

Mactra — continued.

Plate

Figure

Pape

semistriata, Deshayes, .

vilrea, Chemnitz,

154

Mactrid*, ....

Mactrin^, ....

Mactrinula plicataria.

:: j

57
4,6,244,246

llAI.I.ETIA, ....

323, 324

arrouana, n. sp., .

XX.

7-76

in, 214

cuneata, n. sp..

XX.

10-lOa

8, 247

dunkeri, n. sp.,

323

excisa, .

232

gigantea. Smith, .

13, 244

obtasa, Sars,

...

9, 245

pallida, n. sp..

XX.

8-8<i

12, 246

vencriforniis, n. sji..

XX.

9-9(1

8, 246, 248

Malleus, ....

284

albus, Lamarck, .

17, 284

Maete-sia,

striata, {LimU), .

19, 27

MIeretrix,

222

philippinarum,

...

141

MODIOLA,

275

anlillarum, .

276

appendiculata, Philippi,

726

arborescens, Chemnitz,

276

barbata (Linni), .

...

22, 275

capax, .

...

275

cumingiana, (Dunker), .

Keeve, ...

278

elegans, Gray,

276

glaberrima, Dunker,

15, 275, 276

{Lithophagii-s) antiUa
rum, Philippi,

276

perfragilis, Duuker,

276

strigata. Reeve,

278

subclavata, Libassi,

279

sulcata, (Lamarck), Reeve,

272

trapesina, Lamarck,

279

trapczina.

279

vitrea, MuUcr,

5-5c

282
19, 20, 275

watsoni, n. sp.,

XVI.

276

Modiolarca, .

270

kerguelensis, n. sp..

XVI.

8-8(1

13, 280

trapezina, (Lamarck),

13, 24, 279

Modiolaria, .

...

4, 278

barbata.

...

278

cumingiana, Dunker,

15, 278

cuneata, Gould,

XVI.

7-7o

5, 15, 278

fischeri, n. sp..

...

279

lanigera, Dunker, .

15, 278

marmorata, Forbes,

279

semigranata, Reeve,

9, 279

varicosa, Gould, .

15, 279

MONTACUTA, .

203, 204

acuminata, n. sp., .

XII.

3-36

17, 205

angasi, m. sp..

XII.

2-26

14, 204

cylindracea, «. sp..

XII.

4-46

8, 206, 208

jerruginosa, llontagu, .

...

208

occidentalis, n. sp..

SlI.

5-56

8, 20 1;

336

THE VOYAGE OF H.M.S. CHALLENGER.

MONTACUTA— COft^/WMfrf. Plate

Figure Page

jVa ssa — cant in ued.

Plate

Figure

Page

paula, {J. Admns), ■ xii.

1-li 18, 203

papulosa.

...

221

piira, n. sp., . . . xii.

6-6ft 7, 9, 207

Nejera

...

... 4

, 6, 35, 241

MULINBA isabelleaiia,

abbreviala, Forbes,

MVA,

adunca, Gould,

duhia, Pennant, .

angasi, n. sp.,

IX.

2-2*

15, 35, 47

japonica,

angularis, Jeffreys,

sp.,

17, 56

arctica, Sars,

suhorlwidaris, Montagu,

201

arcuata, Dall,

Myadora brcvis, Eeeve, .

azorica, n. sp..

7-76

10, 35, 141

Myid^

bicarinata, Jeffreys,

Myin^

brazieri, n. sp.,

I.X.

3-36

14, 37, 51

Myochama, .

capensis, n. sp., .

IX.

5-56

12, 35, 45

anomioides, Slutefibury,

14, 15, 63

casta. Hinds, .

l:cp2>cUiana, A. Adams, .

chinensis, Gray,

35, 48

strangei, A. Adams,

cireinata, Jeffreys, .

4-46 9, 10, 35, 42

stiitchburyi, A. Adams, .

claviculata, Dull, .

IX.

8-86 7,

8, 38, 52, 53

tabida, Eeeve,

concinna. Hinds, .

transversa, A. Adams, .

congenita, n. sp., .

1-16

8, 38, 53

Mtodora

64, 220

consociata, n. sp., .

IX.

7-76

8, 35, 41

angustata, (Angas),

15, 68

contracta, Jeffreys,

australica, {Reeve),

15, 67, 71

costata, Sowerby, .

brcvis, H. and A. Adams i

costellata, Deshayes,

{iwn Sowerby ), . j

costellata (var. corpuleida

brevis, {Sowerby), .

15, 64

crassa, llonterosato,

crassa, {Stutchbury),

14, 65

ciu'ta, Jeffreys,

... 8,

9, 36, 49, 54

oblonga, Reeve,

65, 67

cuspiilata, Olivi,

pandora-formis, Reeve, .

dcprcssa, Jeffreys, .

pandorifovmis (jSiMfcAiar!/),

15, 64, 67

didyma. Hind?,

... 17, 18, 65, 66

elegans. Hinds,

19, 35, 47

striata, (Quoyand Gaimard), ...

exigica, Jeffreys, .

tincta, Reeve,

fallax, n. sp.,

2-26

17, 36, 49

trigona, Eeeve,

17, 65, 66

filocarinata, re. sp..

5-56

11, 35, 44

Myrina

4, 281

fragilissima, n. s}}..

IX.

1-16

13, 38, 53

coppingeri, n. sj)., . . XVI.

9-96 16, 281

glacialis, Sars,

Mytilicardia {Thecalia) con- i

214

gomerensis, n. sp..

3-36

36, 50

camerata, . . .\

gouldiana. Hinds, .

Mytilid^,

270, 271

gracilis, Jeffreys, .

Mytilin.1;,

272

granulata, Uall,

Mytilus

173, 272

hindsiana, A. Adams, .

35, 45

{Aulacomya) hirsutus, .

273

infiata, Jeffreys,

35, 38, 51

barbatus, Linne, .

275

iridcscens. Hinds, .

bilocularis, liinae, .

271

jeffreysi, Dall,

cubitiis, Say,

272

jitgosa. Wood

cumingianus, Reeve,

271

kerguelenensis, n. sp..

XXIV.

8-86

13, 35, 46

cdulis, Linne,

... 5,15,24,25,272

lamellifcra, Dall, .

37, 41

exustns, {Lamarck), Eeeve,

11, 272

latisiUcata, Tenison-Woo

ds, ...

hirsutus, Lamarck;

15, 273

liinatula, Dall,

35, 46

horriclus, Dunker, .

274

meridionalis, n. sp.,

I.X.

6-66

1.3, 35, 43

kerguelensis, n. s/)., . xvi.

4-4« 13, 274

moluecana, Adams and I

leeve, ...

magellanicus, C%«)n?w<2, .

... 5,13,16,24,272

muUicostata,'y exriW and S

^mith,...

meridionalis, n. sp., . xvi.

3-3a 13, 273, 274

murrayi, ?;. sp. ,

woodcut.

319

modiohis.

275

nnsuta, A. Adams,

nicobaricus, Chemnitz, .

271

iwbilis, A. Adams,

pilosiis, Recluz,

271

notabilis, Jeffreys, .

(Stavelia) horridus, X)Mnfer, ...

17, 274

obesa, Lovin,

... 5

10, 35, 43, 46

sulcatus, (Lamarck ?), Eecvc, ...

17, 272

papyna, Jeffreys, . '

tortus, (Dunker), Reeve,

274

patagonica, n. sp., .

VII.

5-56

23, 39

variabilis, Krauss,

272

pectinata. Carpenter,

AUSSA glans, .

221

pelludda, Stimpsoii,

REPORT ON TPIE LAMELLIBRANCHIATA.

337

Ukjera— cow/JnMa/.

Plate

Figure

Page

philipjyinensis^ A. Adams )
(nee Iliiuls), . . 1

philippincnsis, Hinds,

platensis, n. sp., .

IX.

4-46

24, 35, 45

pulchella, H. Adams,

p\ira, Augas,

{Rhinomya) rugaia, Angas

(non A. Adams),

rosea, Hinds,

rostrata, Spengler,

...

- i

35,40,41,45
47, 48

rugata, A. Adams,

...

niginosa, Jeffreys, .

semistrigosa, Jeffreys,

3.5, 37

singaporerms, Hinds,

sp., ....

7, 8, 48

striata, Jeffreys, .

subtorla, Sars,

sulcifera, Jeffreys,

tasmaiiica, Tenison-Woods

teres, Jeffreys,

...

7, 35, 36, 51

trailli, Hutton,

...

trigona. Hinds,

...

truncata, Jeffreys, .

...

wollastonii, n. sp.,
NUCINELLA, ....

6-6&

9, 35, 39, 40
231

miliaris, (Deshayes ?), S. Wood,

230, 231

NUCULA

4, 6, 225

(Acila) mirabilis, A. Adains, ...

22, 230

coriuloidcs, Seguenza, .

...

228

crassa. Hinds,

237

culebrensis, ?i. sp..

SVIII.

11-1 la

8, 228

dccussata,

...

226

dilatata, Philippi, .

...

233

excisa, Philippi,

232

grayi, d'Orbigny, .

...

225

lata. Hinds, .

...

235

miliaris.

231

mirabilis, A. Adams,

230

niponica, n. sp., .

XVIII.

8-8(1

22, 226

nitidula, A. Adams,

15, 225

obliqna, Lamarek,

18, 19, 225

pernambucensis, n. sp..

XYIII.

10-lOa

11, 227

profundorum, n. sp.,

XVIII.

13-13a;

22 229

reticulata, Jeffreys,

10, 229

19, 226

torresi, n. sp. ,

XVI I r.

9-9ns

17, 227

iiruguayensis, Smith,

xviir.

12-12*

25, 229

NnCt7LID.E, ....

225

NuCtJLINA, ....

230, 231

munita. Carpenter,

231

ovalis, {S. Wood),

XIX.

1-lft

4, 12, 230

OcuLiNA iermudiania, .

276

OSTKEA,

...

318

arata, Gmelin,

295

hullata. Born,

292

gihba, Linne,

295

imbricata, Lamarck,

19, 318

inflata, Gmelin,

292

(ZOOL. CHALU EXP. PART XXXV. 1885.)

OsTREA — continued. Plate Figure

pleiironcctcs, Linne,
pusio, Linn^,
senaloria, Gmelin,

0STREID.S1,

Pallium vitreum, Chemnitz,
Pandora Irevis, Sowerby,
Pandorin^, .

PAPIIIIDiE,

Pbcchiolia, .

ahyssicola, Sars,

angulaia, Jeffreys,

gibbosa, Jeffreys, .

insculpta, Jeffreys,

sinuosa, Jeffreys, .

suhquadrata, Jeffreys,

tomata, (Jeffreys),
Pbcten, ....
Peoten

amicus, n. sp.,

antomii, Philippi, ;

aratus, .

asperrimus, Lamarck,

australii, Philippi,

australis, Sowerby {non
Philippi),

aviculoides, n. sp.,

bifrons,

blandus. Reeve,

bullatus,

clathratus, Martens,

cloactus, Reeve,

commutatus, Monterosato,

corallinoides, d'Orbigny,

crassicostatus, Sowerby, .

cristularis, Adams and Reeve, ...

cruentatiis, Keeve, .

culebrensis, 7!. sp., . XXII.

distinctus, n. sp., . . xxii.

flexuosus, Poll,

fragilis, Jeffreys,

fricatus. Reeve,

fumatus. Reeve,

gibbus, {Linni),

gloriosus, Reeve,

idaeus. Reeve,

(Janira) fumatus. Reeve, .

(Janira) laqueatus, jSowcrJi/, ...

kermadecensis, n. sp., . XXI.

kuhnholtzi, Bemardi, .

laqueattts, Sowerby,

layardi, Reeve,

lemniscatus, ifccrc,

lenliginosus. Reeve,

Icopardus, Reeve, (var. Solaris), ...

limatula, JJc<;»e, var., . xxi.

miniaccus, (Lamarck),
Sowerby,

murrayi, n. sp., . . XXII.

nobilis, Reevo,

5-5(1

4-4(1

6-63
3-3a

7-7a

5-5o

1-1 a

Page

308

295

300

318

303

165

166

166, 170

294

16, 301

307

295

14, 294
294

294

13, .305
299
300
292

13, 305

300

296, 297

10, 300

300

8, 306

13, 304
299
302, 303
300
307
9, 295, 296
300
295

15, 307
22, 307

16, 302
299, 300

307
300

20, 298
298

21, 299
12, 297

300

16, 303
300

Mm 43

338

THE VOYAGE OF H.M.S. CHALLENGER.

Pecten — coiHinunl. Plate

Figure

Page

Plate Figure Page

noclosus, Linne,

300

PETEICOUD.E,

113

nodulifcnis, Sowerby, .

300

Phaseolicama majeWajiica, Rousseau,

279

noronhensis, n. sp., . xxi.

i-ib

11, 296

trnpczina, . . ;

279

pafcigonicus, King,

24, 294

Pholadid^

pcs-fclis.

301

PHOLADINiB

philippii, R(cluz, .

... 5,

10,

296, 297

Pholas Striata, Linne, .

plcurmuctcs, .

308

Pinna,

283

prunum, Eeeve,

294

carolinen3is, .

283

pscudolmia, Soviahy, .

300

subviridis. Reeve, .

283

pudicus, n. sp., . . XXI.

8-Sb

13, 302

tasmanica, Tenison- Woods (X), ..

14, 283

pusio, [Limii),

10, 295

VlSSlDM,

283

reticulatns, Reeve, .

300

Pleurodos\ .

231

nifirculiatiis. Reeve,

294

Pleurodonta, . . .

231

rtigosas, Sowerby, .

300

Pleuronectia fwciVZa, Jeffreys,

317

semiosiis, Reeve,

300

Pleurodon ovalis, S. Wood, .

2-30

senatorius, (G-mcUn), var

,21,300

Plicatula

286

Solaris, Sowerby, .

299

imbricata.

287

S, 307

ramosa, Lamarck,

25, 286

striatus, var. furtivus, .

301

sp.,

20, 287

subhyalinus, n. sp., . xxii.

2-2a

24, 304

Poromya,

sulcatus, Miillcr. var., .

7, 295

australis, n. sp..

I. 2-26 17, 54

tasmanicits, A. Adams andAngas,

299

granulata, Nyst,

testae, Bivona,

10, 301

Isevis, n. sp. , .

I. 3-36 17, 55

tcsludineiis. Reeve,

300

jOTifcAcHn, Adams and Reeve,

tigris

301

Prasika borbonica, Deshayes, .

269

triradiatus, Keeve,

300

PSAMMOEIA, .

79, 90, 104

undulatus, Sowerby,

14, 299

angusta, Deshayes,

1 5,20, 21, 22,23,

anoniala, Deshayes,

17, 95

vitreus, [Chemnitz),

I24

, 303, 304

castrensis, (Spengler),

16, 91

vilreus. King,

303

compta, Deshayes, .

PEOTINIDa:

294

convcxa. Reeve,

92, 93

PECTUNCULINiE,

248

costulata, Turton, .

10, 90

Pectunculi-.s,

4, 250

disco7-s, Philippi, .

auritus,

257

intermedia, Deshayes,

10,94

beddomei, n. sp., . . xviir.

-lb 14,63,252,253

lineolata. Gray,

15, 92

cmiceUatus, Reeve,

256

malaccana, Reeve,

flabcUahis, Tenison -Woods,

253

menkeana. Reeve, .

formosus, Becve, .

10, 251

modesta, Deshayes,

14, 95

holosericus, Reeve,

15,

63, 251

oriens, Deshayes, .

91, 92

laticostatus, Quoy and Gaimard,

253

pallida, i>estei/es, .

18, 93, 95

miimtus, Philippi,

258

pucUa, Deshayes, .

93, 94

novcc-guinecjisis, Angas, .

253

pulcherrima, Deshayes, .

16, 91

pectiuatus, (Qinelin),

11, 250

radiata, Dunker, .

pilostis, .

250

solida. Gray, .

siciilus, ....

250

solida, Philippi,

stellatus, (Bruguiire), .

10,

250, 251

sp..

20, 92

striatularis, {Lamarck ?), Eeeve,

15,

21, 251

striata, Deshayes, .

93, 94

vitreus, Lanuirck, .

19, 253

suffusa, Reeve,

Pedum,

270

tellinceformis, Deshayes,

93, 94

Pelectpoda

tenuis. Reeve (non Deshayes), . .

Peeiploma, ....

wei7ikauffi, Cto&se,

compressa, d'0rbu)7ij/, .

25, 71

zonalis, {Lamarck),

14, 93, 94

Pekna,

2S5

PsAMMOBIIN.a,

glaberrima, .

275

PSAMMOT.XA zonalis, Lamarck,

(Isognomon) samoensis, Baird, ...

285

Pythina

204

samoensis, Baird, .

23, 285

arcuata, A. Adams,

204

vitvea,, Seeve,

23, 285

cumingii, A. Adams,

204

Petricola,

113

deshayesiana. Hinds,

204

lapicida, (Chemnitz), juv..

17, 113

7nactroidcs, Hanley,

204

REPORT ON THE LAMELLIBRANCHIATA.

339

Pythina — continued.

Plate

Figure

Pago

?>oi,mi— continued.

Plate Figure Page

nuculoides, Hanley,

204

sloanii, Gray, . .

14, 78

paula, A. Adams, .

203, 204

solidus, Gray,

peculiaris, A. Adams, .

203

versicolor, Philippi,

stowei, Hutton,

204

SOLENELLA gigantca, Smith,

244

triangularis, A. Adams,

204

S0LENID.S;,

Radula (Limatula) pyrpncm, .

292

Spathophora,

{Manlellum) angulata, .

289

SPONDTLlDi), .

286

(Maniellum) orientalis, .

289

Spondtltjs, .

286,318,323,326

Eaeta,

...

barbadensis, Petiver,

286

canaliculatd,

hcrinaceus, Chenu,

286

pulchella, [Adams and Beeve)

...

22, 56

ostreoides, n. sp., .

326

Rhinomya

Victoria!, Sowerby, .

19, 286

Sarepta

4, 6, 243

icrighiianus, Crosse,

286

abyssicola, n. sp., .

XX.

6-6«. 4,

22, 23, 243

zonalis, Lamarck, .

17, 286

speciosa, A. Adams,

244

Stavelia torta.

274

Saxioava, ....

Syndosmya, .

arctica, Linne,

'.'.'. j*.

9, 12, 13,

longiaxllis, .

1 14

, 24, 78

Tapes, ....

131

spinifera, Sowerby,

(Amygdala) exalbida, (Chemnitz),

24, 117

SAXICAVID.B, ....

(Amygdala) fabageUa, Deshayes,

14, 116

SCAPHARCA, ....

326

(Amygdala) intermedia, 1

15, 116

ScROBicuLARiA longicallus,

Quay and Gaimard, \

ScBOBICULARIIDa;, .

(Chione) undulata,

f3,

83, 106

rfuro, Gmelin,

114

Semele, . . . . ■

■■• \108, 111

fabagclla, Deshayes,

116

(Abra) braziliensis, n. sp.,

2-26

11, 85

grata, Deshayes, .

113, 114

(Abra) longicallus, (Scacchi),

intermedia, .

116

(Abra) pbilippinensis, n. sp.,

Z-Zd

21, 86

obscurata, Deshayes,

.. 20, 113, 114

. .1 *'

9, 10, 11,

(Paratapes) semirugata, (Philippi),

18, 115

(Abra) profundorum, n. sp..

5-56 j 22

,88

(Paratapes) textrix, (Chemnitz),

14, 114, 115

(Abra) regularis, n. sp., .

4-46

17, 87

(Paratapes) undulata, (Bom), ...

19, 22, 115

amabilis, A. Ad/nns,

19, 83

polita, Sowerby,

115

infans, n. sp.,

1-16

17, 84

quadriradiata, Veshayea,

113, 114

obliqua, ( Wood) jun.

11, 84

rimosa, .

115

(Theora) iridescens, (Hinds),

6-66

20, 89

similis, Deshayes, .

114

Semelinj;, ....

«'»w7!S, Reeve (»j<»i Deshayes), ...

113

Septifer

271

(Textrix) semirugata.

115

bilocularis, (Linne),

16, 271

textile, Gmelin,

114

cumingii, Recluz, .

271

tmdulata. Born,

114, 115

SiLENiA, n. gen..

4, 75

Tapesin^, ....

113

sarsii, n. sp '

XXV.

4-46 4,

13, 25, 75

Tellina, ....

96, 106, 108

SOLECURTUS, ....

(Angulus) lux, Hanley, var., ...

19, 102

abbrcviatus, Gould,

(Angulus) natalensis, Krauss, ...

12, 102

antiqxmtus, .

(Angulus ?) rhomboides,

16, 17, 103

(Azor) coarctatus, (Gmelin),

18, 79

Quay and [Gaimard,

oblcmgus.

(Angulus) valtonis, Hanley,

16, 102

scheepniakeri,

(Angulus) vemalis, iya7i%,

20, 103

solidus,

(Arcopagia) casta, .

109

SOLEMTA

208

(Arcopagia) elegantis- ) j^. ^_

56 18, 105

australis,

209

sima, n. sp., . . •

parkinsonii, Gray,

209

(Arcopagia) pretiosa, X»esAay«, ...

16, 104

patagonica, n. sp.,.

xr.

1-la

24, 208

angtista, ...

S0LEMTID.S;, . .

208

asperrima, Hanley,

100

SOLEN

bifaria, Baird, . .

103, 104

angiistior, &c., Chemnitz,

...

cascus, Sowerby, .

103

bullatus, Linn^,

...

161

( ^.) casU, Hanky, .

. 18,106,109,110

castrcnsis, Spengler,

clathrata, (Quoy), Deshayes

103

coarctatus, Gmelin,

compacta, ;;. sp., . . 111. 9-

■9c 18, 99

philippianus, Dunker, .

compta, Gould,

103, 104

340

THE VOYAGE OF H.M.S. CHALLENGEE.

Tellina — continued. Plate

Figure

Page

Thracja— continued. Plate

Figure

Page

costnta, Sowerhy, .

104

modesta, Angas, .

15, 71

diluta, n. s]\.

IV.

7-76

17,

106, 108

myodoroides, n. sp..

VI.

6-C6

14, 70

( ?) doiiiicina, Linni,

100, 105

novo-zelandica. Reeve, .

67, 68

( ?) fijiensis, Soiocrby,

106, 107

truncata. Brown, .

68, 69

flexuosn, Montagu,

192

watsoni, n. sp..

VI.

5-56

14, 69

fiexiiosa, Turton, .

187

Thraciin^

galaliva, Lamarclc,

TICHOGONIA bilocularis, Kiister,

271

glabrclla, Deshayes,

101

kraussii, Kiister, .

271

gubemaculum, Hanley, .

...

17,

98
18, 106,

TiVELA undulosa, .
Tkidacna

132

170

( ?) languida, n. s]\,

IV.

S-Sb

110

crocea, Lamarck, .

17, 170

lauta, Gould,

103

gigas, . . . .

171

Jongicallus, Scacchi,

rudis, . . . .

171

lux, Hanley, .

102, 103

squamosa.

171

(Macoma) arafurensis, n. sp.,

IV,

6-66

19, 98

Tr.IDAONIDvE

170

(Macoma) consociata, n.sp.,

IV.

4-ic

20, 96

TRiGoyELLA incarnata, .

...

(Macoma) uruguayensis, «. sp.,

IV.

5-56

25, 97

pusilla, Angas (nmi A, Adams'

murrayi, n. sp.,

III.

8-86

17, 98

TniGONIA, , . . .

224

natalcnsis, Krauss,

102

julrcsii, A. Adams,

224

obliqua, Wood,

lamarckii, Cfray, .

15,63,224,225

perna, ....

107

margaritacea, Lamarck,

14, 224

(Pcronella) pura, H. Adams,

103, 104

pectinata, Lamarck,

224

pretiosa, Deshayes,

104, 105

uniophora, Gray, .

17, 19, 224

pulchcrrinia, Sowerby, ,

100

TRIGONIID.E, , . , .

224

rlwmboides, Quoy and Gaimard,

103

Trigonulina ornaia, d'Orbigny,

165, 166

{ ?) semen, Hanley,

16,
106

17, IS,

UNGULINIDiE, . , , ,

195

,111,112

Venerid,e, ....

113, 126, 222

semiaspera, Deshayes, .

100

Venerinj), . .

117

( ?) semitovta, Sowerby,

14,

106, 111

Venerupis, , , , .

113

silkula, (Deshayes), Sowerby,

103, 104

irus, (Linni),

10, 113

squamulosa, .

...

100

Venus,

4, 117, 222

(Telliuclla) charlottse, n. sp.,

IV.

1-1 c

15, 100

cegrota. Reeve,

120

(Telliuella) huttoni, n. sp..

IV.

2-2i-

15, 101

(Anaitis) caloph.ylla.

122

(Tellinella) verrucosa, Hanlcij,

16, 100

(Anailis)foliacea, .

122

( ?) tenuilamellata, n. sp.

IV.

9-96

18,

106, 110

(Anaitis) paphia, LinnA, var.,

10, 121

( ?) tenuilirata, Sowerby,

16,17,106,710

(Antigona) lamellaris,
{Schuiiiacher),

18, 121

textarata, Sowerby,

...

103

inmcata, Jonas,

...

(Antigona) puerpera, Linni, var,,

16, 120

■umbonella, Lamarck,

auslralis, Quoy and Gaimard,

152

tmi/asciala, Sowerby, .

103

auslralis, Sowerby,

131

valtonis, Hanley, .

102

calophylla, Philippi,

...

122, 123

vernalis.

102, 103

casina, Linne,

120

verrucosa, Hanley,

100

(Chamelaea) mesodesma, i

4, 12, 15, 131

Tellinella

107

Quoy and Gaimard, \

Tellinid,e

...

90, 106

(Chione) calophylla, Philippi,

... 14, 18, 20, 122

Tellinin^, ....

....

(Chione) foliacea, Philippi,

17, 18, 122

Teredinin^, ....

(Chione) infans, n. sp., .

III,

3-3J

18, 128

Teredo,

(Chione) jacksoni, n. sp.,

III.

2-2c

14, 123

16, 27

(Chione) levukensis, n. sp.,

III.

6-66

16, 128

Thecalia macrotJieca, Adams i
and Angas, . . . (

(Chione) lionota, ?i. sp., .

Ill,

7-76

18, 20, 126

214, 215

(Chione) marica, LinnA, .

16, 125

concamerata.

215

(Chione) mindanensis, n. sp..

III.

4-46

20, 130

Theora

(Chione) ovata, Pennant,

9, 124

iridescens.

...

(Chione) recognita, n. sp..

Ill,

5-5c

21, 125

lubrica, Gould,

(Chione) scabra, Hanley,

22, 124

(Neccra) fragile, A. Adams,

(Chione) striatissima, Soivcrby,

14, 124

Theacia

(Circe) scripta.

...

141

australica. Reeve, .

...

67, 68

(Oircomphalus) calophylla.

122

meridionalis, n. sp.,

vr.

4-45

, [13, 68

claihrata, Dcshaye:?,

...

120, 121

REPORT ON THE LAMELLIBRANCHIATA.

341

Venus — continued. Plato Figure

costclli/cra, AisLVas ani 'Reeve, ...
craissd, Quoy and Gaimard,
crispata, Deshayes,
cuminyii, Sowerby,
cypria, Sowerby, .
(Cytherca {Crista)) ausiralis, ...
(Cytherea (Crista)) gibhia,
(Cytherea, sect Caryatis) ^

helrcea, Romer,
{CytJicrca, sect. Caryatis) j

soligcna, Romer,
dciiticulcda, ...
effossa, Bivona,
exalbida, Chemnitz,
foliacea, Philippi, .

gayi, Hupe,

(Gompliina) undulosa, Lamarck,

hyalina, Pliilippi, .

intermedia, Quoy and Gaimard,

lacerata, Hanley, .

lamarckii,

lapicida, Chemnitz,

largilliarti, Philippi,

(Leukoma) australis, (SoMJeri)/, ...

listeri, Gray, .

magnifiea, Hanley,

marica, Linne,

mcsorfcsma, Quoy and Gaimard,

minima, Montagu,

multicostata, Sowerby, .

nodulosa, Sowerby,

ovata, Pennant,

paphia, Linne,

papyracea, Gray, .

philomela, n. sp., . . ii. 7-76

puerpera, Linne, .

quadriradiata,

recognita, n. sp., .

resticulata, Sowerby,

rimosa, Philippi, .

scabra, Hanley,

scripta, Linne,

semirugata, Philippi, .

sowerbyi, Deshayes,

spissa, Deshayes, .

spurca, Sowerby, .

striatissima, Sowerby, .

stutMuryi, ...

Page

Venus — continued.

Plato

Figure

Page

126

suhrostrata, Wood,

121

131

fehuclcJia, d'Orbigny,

137

120

textrix, Chemnitz, .

114

122

thiara, ....

...

122

tiara, ....

122, 123

142

ligerina, Linne,

179

143

torresiana, Smith, .

in.

1-le

18, 118

138, 139

undulata,
undulosa, Lamarck,

115
132

139

varicosa, Sowerby,

122

(Ventricola) casina, LinnA,

, 10, 120

131

(Ventricola) effossa, Bivona,

, 10, 120

120

violncea, Quoy and Gaimard,

131

117

Verticordia,

4, 6

122

VERTICORDrA

..•

165, 169

118

acuticostata, .

167

18, 132

areno3a = woodii, .

...

165

154
116

australiensis, n. sp..

XXV.

6-66

jl7,
1170

165, 167,

120

cardiiformis, J. Sowerby,

165, 167

121

ccelata, Verrill,

165

113
116

deshayesiana, Fischer, .

165

11. 17,
,167

14, 131

ekgantissima, Dall,

165

120, 121

fischei-iana, Dall, .

165

120, 121

granulata, Seguenza,

165, 166

125, 126

japonica, A. Adams,

165, 167

5, 131

multicostata, A. Adams,

165,

166, 168

148

novemcostata, Adams and Reeve,

165

121

ornata, d'Orbigny, var..

166, 170

121
124

quadrata, n. sp., .

XXV.

8-86

10,
170

165, 169,

121

tomata, [Jeffreys),

XXV.

9-96

, 11, 170

154
12, 117

woodii, n. sp..

XXV.

:-«

8,
169

11, 168,
170

120, 121

Verticokdiidj:,

165

113

VoLAfumata,

307

125, 126

laqtceata.

...

307

120, 121

VoLSBLLA glaberrima, Dunker,

275

115

Vulsella, ....

270

124

YOLDIA,

242

141

abyssicola, Sars,

245

115

isonota. Martens, .

XX.

6-56

13, 242

120

hoylei, n. sp..

woodcut.

320

131

japoniea, Adams and Reeve,

242

131

lischkei, n. sp..

XX.

4-46

22, 242

124

obtusa

245

128

subsequilateralis, Smith,

...

13, 243

PLATE T.

(ZOOL. CHALL. EXP.— PART XXXV. — 1885.)— Mm.

PLATE I.

Figs. 1-le. Dosinia deshayesii, A. Adams,

Figs. 2-2e. Dosinia circinaria, Deshayes,

Figs. 3-3e. Dosinia mira, n. sp.,

Figs. 4-4e. Cytherea (Callista) disrivpta, Sowerby,

Figs. 5-5e. Cytherea (Callista) multistriata, Sowerby,

Figs. 6-66. Cytherea {Callista) roseotincta, u. sp.,

7c. Cytherea (Caryatis) coxeni, Smith, .

86. Cytherea {Garyatis) regularis, n. sp.,

Figs. 7

Figs. 8

PAGE

149
150
152
135
134
136
139
140

The Voyage of H.MS "Challenger"

Lamellibrancliia-

7a.

THE CSMBRIDCE SCIENTIFIC INSTRUMENT COMPHNV

PLATE II.

Figs. 1-16. Circe hermiidensis, n. sp., .

Figs. 2-2e. Circe arnica, n. sp.,

Figs. 3-36. Circe jucunda, u. sp.,

Figs. 4-4e. Circe australis (Angas).

Figs. 5-5e. Circe gordoni, n. sp.,

Figs. 6-66. Circe ohliquissima, u. sp., .

Figs. 7-76. Vemis 2^hiIomeIa, n. si:>.,

PAGE

143
145
144
148
146
149
117

The Voyage of H,MS"Cha]Ienger"

Lamellibrancliiata PI II

V '

6b.

-5^

6a.

7a.

THE CAVBRIOGE SCIENTIFIC INSTRUMENT C0MP4NV

PLATE III.

(ZOOL. CHALF,. EXP. — PART XXXV. — 1885.) — Mm.

PLATE III.

Figs. 1-le.

Figs. 2-2e.

Figs. 3-36.
Figs. 4-46.
Figs. 5-5e.
Fies. 6-66.

Figs. 7-76.

Fies. 8-86.

Figs. 9-9«.

Venus torresiana, Smith,
Vemis {Chioiic) jacksoni, n. sp.,
Vemis {Chione) infans, n. sp.,
Venus (Chione) mmdanensis, n. sp.,
Venus (Chione) recognita, n. sp.,
Venus (Chio7ie) levukensis, n. sp.,
Venus (Chione) lionota, n. sp.,
Tellina murrayi, ii. sp.,
Tellina compacta, n. sp.

118
123
128
130
125
128
126
98
99

Th£ Voyage of I.MS "Challenger."

LamellibrancMata PL IH

THE CAMBRIDGE SCI£N71FIC INSTRUMENT COMPANY

PLATE IV.

Figs. 1-lc.

Figs. 2-2c.

Fies. 3-36.

Figs. 4-4c.

Figs. 5-56.

Figs. 6-66.

Figs. 7-7}>.
Figs. 8-86.

Figs. 9-96.

Tellina (Tellinella) charlottce, n. sp.,
Tellina {Tellinella) huttoni, n. sp., .
Tellina {Arcopagia) elegantissima, n. sp.,
Tellina (Macoma) consociata, n. sp.,
Tellina (Macoma) urnguayensis, n. sp.,
Tellina [Macoma) arafurensis, n. sp.,

Tellina ( ?) diluta, n. sp.,

Tellina ( ?) languida, n. sp.,

Tellina ( ?) tenuilamellata, n. sp..

PAGE

100

101

105

108

110

The Voyage of H.MSI'Challengfii-"

'\-

,/"

'11^

THE CAMBRIDGE SCIENTlFin JNSTRUMF

PLATE V.

ZOOL. OHALL. EXP. — PART ixxv. — 1885.) — Mm.

PLATE V.

Figs. 1-16.
Figs. 2-2b.
Figs. 3-3f/.
Figs. 4-46.
Figs. 5-56.
Figs. 6-66.
Figs. 7-7c.
Figs. 8-8e.

Figs. 9-96.

Semele infans, n. sp.,
Semele [Ahra) hraziliensis, n. sp., .
Semele (Abra) pkilippwensis, ii. sp.,
Semele {Ahra) regularis, n. sp.,
Semele {Ahra) i)rofinidorum, n. sp.,
Semele {Theora) iridescens (Hinds),
Mactra incerto, u. sp.,
Mactra pusilla A. Adams, .
Mactra jojcksonensis, n. sp.,

PAGE

84
85
86
87
88
89
59
60
62

The Voyage of H.M S "Cha]Ien|er"

LameUibrancliiata PL Y.

THE CiMBH.DOE SCIENTIFIC ;lJSTflUMEM COMPlNv

PLATE YJ.

PLATE VI.

Figs. l-lb.
Figs. 2-26.
Figs. 3-31.
Figs. 4-4fe.
Figs. 5-5b.
Figs. 6-66.
Figs. 7-7h.
Figs. 8-86.
Figs. 9-96.

Davila (?) umbonata, n. sp..
Ervilia suhcancellata, n. sp.,
Lyonsia formosa, Jeffreys, .
Thracia meridionalis, n. sp..
Thracia ivatsoni, n. sp.,
Thracia myodoroides, n. sp..
Callocardia (?) adamsii, n. sp..
Callocardia (?) atlantica, n. sp.
Callocardia (?) pacijica, n. sp. ,

PAGE
81

154

157

156

The Voyage of H.MS "Challenger"

Lcmelhbranchiata PI TI

la.

2a.

ba.

iC INSTRUMENT COM^AN^

PLATE VII.

(ZOOL. CHALL. EXP.— PART XXXV. — 1885.)— Mm.

PLATE \^II.

Figs. 1-1 />. Clavagella tor res i, n. sp.,

Figs. 2-26. Gastrochcena lamellosa, Deshayes,

Fig.s. 3-36. Corbida scaphoides, Hiiid.s, .

Figs. 4-46. Corbula philippu, n. sp.,

Figs. 5-56. Neoera patagonica, n. sp., .

PAGE

28
28
32
33
39

Jm'

5b.

4 a.

J +

tb.

lilt Ct«B'iinGE SCIENTIFIC IMSTBUHENT COMDiNV

PLATE YIII.

PLATE VIIT.

PAGE

Figs. l-lc. Cardm)a{Bucardium.)mirabile,'Deshai.yes,. . . . 159

Figs. 2-26. Cardium {Acanthocardium) sueziense, Issel, . . . 158

Figs. 3-36. Cardium (Papyridea) trai/.n-ersale, Deahayes, . . . 162

Figs. 4-46. Cardium (Fragum) torresi. n. s]i.. . . . . . 164

3. "Challenger"

711!

J^S.

2 a

41)

•ia

THE C4MBRi0r.E Si;iE\

PLATE K,

(zooL. CHALL. Exr. — PART XXXV. — 1885.) — Mm.

PLATE IX.

I'AGE

Figs. l-lh. Neceva fmgilissima , n. sp., . . . • • • 53

Figs. -l-lh. Necera angasi, n. sp., . • • • • • '^'^

Figs. 3-36. Necera hrazieri, n. sp., . . • • • ■ 51

Figs. i-ih. Necera platensis, n. sp., ....•• 45

Figs. 5-5/). Necera caj^ensis, n. sp., . - • • • • 45

Fi'Ts. 6-6'). Ncwra meridionali-'i, n. sp., ..... 43

Fio-s. 7-76. Necera comociata, n. sp., ...... 41

Fi^s. 8-86. Necera daviculata. Dull, ...... 52

TKe Voyage of H.M S " Challeager "

LamellibraTi

,:.y

'■"*Sk^\

2 a

la.

Ju.

3b.

51)

■la.

k^^

■^^^^K

ba.

^^^P-

Sh.

THE CAMBRIDGE SCIENTIFIC INSTRUMENT COMPiN<

PLATE X.

PAGE

Figs. 1-16. Necera congemta, n. sp., . • • ■ • • . o^

Figs. 2-2h. Necera fallax, n. sp., ..■•••'*"

Figs. 3-36. Necera gomere'nsis,n. f^i)., . ■ .... 50

Figs. 4-46. iVe«?T( c/rcMirtto, .leflreys, ..■■■■ ^^

Fio-s. 5-56. Necera filocarinata, ii. sp.. ..•••• ^4

Fiffs. 6-66. Necera woUastonii, n. sp., . . ■ •. ■ .40

Figs. 7-76. Necera azorica, n. sp.. . • ■ • • • ^^

F'igs. 8-86. Corhula macgilUvrayi, n. sp., . • • . • • 30

I Voyage of H.MSI'Ohall

LameUibrancUata PL X.

THE CAMBRIDCt SCIENTIFIC INSTRUMENT COMPftNV

PLATE XL

(ZOOL. CHALl.. EXP. — PART XXXV. — 1 885.) — Mr

PLATE XL

figs. 1-la. Solemya imtagoniva, u. sp.,

Figs. 2-2^. Poromya australis, n. sp., .

Figs. S-Sh. Poromya Icevis, u. sp.,

Fios. 4-46. Kcllia auculina, n. sp.,

Figs. 5-5?'. Kellia rotunda (Deshayes), var.,

Figs. 6.-66. Kellia cardiformis, n. sp., .

PAGE

208
54
55
201
202
202

The "Voyage of H. .

2a.

5a.

2b.

Ja.

6 a.

THE CiMBRIQGE SCIENTIFIC INETnuMENT COMPANY

PLATE XIT.

PLATE XII.

Figs. l-\h. Montacuta pavia (A. Adams).
Figs. 2-26. Montacuta angasi, n. sp., .
Flo's. 3-3?*. Montacuta acuminata, n. sp.,
Fics. 4-46. Montacuta cylindracea, n. sp.,
Fios. 5-56. Montacuta occidentalism n. sp.,
Ficrs. 6-66. Montacuta j>iira, n. sp..

PAGE

203
204
205
206
206
207

The Voyage of 'AM S ." CluJlenger"

Lamellibranciiata PL SI.

THE l'lV3r,:05E SCIENTIFIC lUSTOUMENr C:OM''a:iV

PLATE XIII.

(ZOOL. CHAI.L. EXP. — PART XXXV. — 1885.) — Mm.

PLATE XIII.

PAGE

Figs. 1-16. Liicina lamellata (Smith), ..... 173

Figs. 2-26. Lucina ramscuji, n. s\j. , . . . . . .174

Figs. 3-3a. Liicina cristata, n. sp., . . . . . .175

Figs. 4-4a. Lucina {Divaricella) ivpex, n. sp., . . . .176

Figs. 5-5«. Lucina (Codakia) semimdn, Gould, .... 180

Figs. G-6a. Lucina (Codakia) levukana, n. sp., .... 181

Figs. 7-7a. Lucina (Codakia) congenita, n. sp., ... . . 182

Figs. 8-8a. Lucina (Codakia) hawaiiensis, 11. sp., . . ; 183

Figs. 9-9a. Lucina, (Codakia) Jijiensis, n. sp., .... 184

Figs. 10-lOa. Lucina (Loripes) desiderata, 11. sp., .... 185

Figs. 11-116. Lucina (Loripes f) jaclcsoniensis,n. a^., .... 185

Figs. 12-1 2a. Lucina (Loripes f) gordoni, n. s.^., .... 186

The Voyage of H.MS "Challenger"

Lamell.i.

.<<%^

THE C«MBRiOOl SCIENTIFIC INSTRUMENT COMPANY

PLATE XIV.

Fio-s.

Figs.

Figs.
Figs.

Figs.

1-la. Cnjptodon watsoni, n. sp.,
2-2a. Cryptodon moseleyi, n. sp.,
3-3a. Cryptodon falklandicus, n. sp.,
4-4((. Cryptodon rufolineatus, n. sp.,
5-5(f. Cryptodon luzonicus, n. sp.,
6-G((. Cryptodon marionensis, n. sp.,
7-7((. Diplodonta siihgramdosa, ii. sp.,
8-8a. Diplodonta scalpta, n. sp.,
9-9f(. Diplodonta corpulenta, n. sp.,
10-lOa. Diplodonta subglobosa, n. sp.,
ll-llo. Diplodonta conspicua, n. sp.,
12-1 2a. Diplodonta amhoinensis, n. sp.,

PAGE

188
189
190
191
192
194
195
196
196
197
198
199

It Voyage of fl.MS"OKaUen«',er"

LameMnn.-lrnv-, PI TY!

4a.

8a.

10 a

I'Ja

7a.

THE CAMBRIDGE SCIENTIFIC JNSTHUMENT COMPANY

PLATE XY

(ZOOL. CHALL. EXP.— PART XXXV. - 1)^8.">.)— l^fni.

PLATE XV.

Figs, l-l(^

Figs. 2-2c.

Figs. 3-36.

Figs. 4-4a.

Fio;s. 5 -5a.

Figs. 6-6a.

Figs. 7 7(;-.

Figs. 8 -8a.

Figs. 9-9o.
Figs. 10-1 Off.

Astarte inacandreun, Smith,
Cardita astartoides, Martens,
Cdi'dita nifiignis, n. sp.,
Cardita dilecfa, n. sp.,
Cardita heddomei, u. sp., .
Carditella exidata, n. sp.,.
Cardiff'Ua cajiensin, n. sp.,
Carditella torresi, n. sp., .
Carditella angasi, n. sp., .
Carditella. infans, n. sp.,

PAGB

209
212
214
213
211
215
216
217
217
218

ThB Voyage of HMS "Challenger"

Lamellibrancluata PI XT

THE CAMBRIDGE SCIENTIFIC INSTRUMENT C0MP4NY

PLATE XVI.

Figs. 1-1 a.

Figs. 2-2o.

Figs. 3-3a.

Figs. 4-4a.

Figs. 5-5c.

Figs. 6-60.

Figs. 7-7rt.

Fiss. 8-8(1.

Figs. 9-96.

Figs.lO-10&.

Crassatella rhomboides, n. sp.
Crassafella tcn'resi, n. sp.. .
Mytilus meridional is, n. sp..
Mytilus Jcergtielenms, n. sp. ,
Modiola watsoni, n. sp.,
Crenella marionensis, n. sp..
Modiolana cvneata, Gould,
Modiolarca Jxrguelensis, n. sp
Myrina coppingen. n. sp.,
Idas dalli, n. sp..

PAGE

219
223
273

274
275
277
278
280
281
281

The Voyage of H.MS !' Challenger

Lasriellibraiichiata PL .'.VI

THE C4MBRID0E SCIENTIFIC INSTRUMENT COMPANY

PLATE XYlf.

(ZOOL. CHALI.. EXP. — PART XXXV. — 1885.)— Ml;

PLATE XVII.

PAGE

Figs. 1-la. Dacvydium occidentcdc, n. .sp., ..... 282

Figs. 2-2a. Dacvydium meridionale, n. sp., ..... 282

Figs. 3-36. A)'ca (Barhatia) radula, A. Adams, .... 260

Figs. 4-46. Area (Barhatia) 2)teroessa, u. .sp., .... 262

Figs. 5-56. Area [Barhatia) corpulenta, n. s})., .... 263

Figs. 6-6a. A^-ea (Aear) eongenita, n. sp., . . . . . 264

Figs. 7-7a. Area, (Scapharea ?) eoiisociata, u. sp., . . . . 266

Figs. 8-8c. Area (Scapharea ?) incEquisculjJta, ii. sp., . . .267

Figs. 9-96. Area (Scapharea?) culehrcnsis, \i. »\)., .... 268

Figs. 10-106. Area (Macrodon) dalli, n. sp., . . . . ■ . 269

he Voyage of H.M S."Chanen|er"

Lamellibrancliiala PI XVII

;

[

"^^

'"^=^l!||j.

lOa.

PLATE XYIII.

PLATE XVIII.

Figs.

Fio;s.

Figs.

1-16. Fectunctdus heddomei, u. sp.,
2-26. Limojms marlonensis, u. sp.,
3-3o. Limopsis pelagica, n. sp.,
4-4«. Limo2)sii< torresi, u. sp., .
5-5«. Limopsis stramira'a,n. sp.,
()-6o. Limopsis hassi, ii. sp.,
7- 7a. Limopsis lata, n. sp.,
8-8r(. Nucida niponica, n. sp., .
9-9«. Nuciihi torresi. ii. sp.,
10-lOfl. Nucida pcrnamhucensis, n. sp.,
11-1 la. Nucida cidehrensis, n. .sp.,
12-126. Nucida urxiguayensis. Smith,
13-13a. Nucida 'profundonuii, n. sp.,

PAGE

252
254
254
255
255
256
257
226
227
227
228
229
229

The Voyage ot H.MS "Challenger"

LameMrancliiata PLUIII

THE CAMBRIDGE SCIENTIFIC INSTRUMENT COMPANY

PLATE XLX.

CzooL. CHALL. EXP. — PAur XXXV. -1 8,^5 ) :\rii

PLATE XIX.

Fisjs

Figs.

l-\b. Niiculiua ovalLi (Searles Wood),

2- '2a. L('<hi .srHU'», n. sp.,

3-Sa. Li'dd decijyieiis, n. sp.,

4-4a. Lcda inaudax, n. sp.,

.5 5o. Lcdd ronfims, \\. si>.,

6-G". Leda soUdida, n. sp.,

7-7 a. Lcdd hehes, n. sp.,

8-8'(. Fjcda despecta, ii. sp.,

9-9a, Leda inopinata, n. sp.,
10-lOa. Leda novce-guineensis, u. sp.,
11-] la. Leda imtwni, ii. .sp..

PAGE

230
231
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233
233
233
234
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The Voyage of H.MS "Challenger"

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Figs. 1-1 rt.
Fio-s. 2-2((.

Figs. 3-3«.

Figs. 4-46.

Figs. 5-56.

Figs. 6-6i».
Figs. 7-76.

Figs. 8-8a.

Fiss. 9-9a.

Figs. 10- 10a.

Leda corhuloides, n. sp., .
Leda necerifoTmis, n. sp., .
Leda ntnisayi, n. sp.,
Yoldia lischkei, n. sp.,
Yoldia isonota. Martens, .
Sarepta abyssicola, n. sp.,
Malletia arruana. n. sp., .
Malletia pallida, ii. sp., .
Malletia veneriformis. n. sp.
Malletia cuneata, u. sp., .

PAOE

239
240
241
242
242
243
244
246
246
247

The Voyage of H.M S "Challenger"

Lamellibraricliieta PI. H,

IHt CAMBRIDGE SCIENTIFIC INSTRUMENT C0MP4NV

PLATE XXI.

^ZOOL. CHALL. ESP. — PART XXXV. — 1885.) — 'Sim.

PLATE XXI.

Figs. 1-1^. Glomus ji'jf'reijd, u. sp.,
Fios. 2-26. Glomus simplex, n. ii\).,
Fiffs. 3-3/>. Glomus incequilateralis, n. sp.,
Fios. i-ib. Pecten )toronhensis, u. sp., .
Fios. b-5n. Pecten limatula, Reeve, var.,
Fior. 6. Pecten amicus, ii. sp.,

Fiofs. 7-7a. Pecten kermadecensis, u. sp..
Figs. 8-8/>. Pecten imdicus, n. sp.,

PAGE

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249
249
296
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PLATE XXII.

Figs. 1-la. Pecten murrayl, n. sp.,
Figs. 2-2rt. Pecten subhijaliiius, n. sp., .
Figs. 3-3a. Pecten distinctus, n. sp.,
Figs. 4-4o. Pecten clathratus, Martens,
Figs. 5-5a. Pecten aviculoides, n. sp., .
Figs. 6-6«. Pecten cidebrensis, n. sp., .
Figs. 7 -7c. Amvssv.im dalli, n. sp..
Figs. 8-8c. Amnsshan ivatsoni, n. sp., .

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.6 Voyage of H,M S "Challenger'

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(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) ^fni

PLATE XXIIL

PAGE

Figs. 1-Ic. Avmssium caduciim, n. sp., ..... 309

Figs. 2-2o. Amvfishan jeffroym, n. sp., . . . . .310

Figs. 3-3?>. Amnssinm torrcsi, n. sp., . . . . . .311

Figs. 4-46. Amussium scitidum, u. sp., ..... 312

Figs. 5-5ffl. Amussrum squamigo-itDi, n. sp., ..... 312

Figs. G-Ga. A7nits,suiiii dh/tquuin, n. sp., ..... 313

Figs. 7-7l>. AmussidDi propinqnum, n. sp., ..... 314

Figs. 8-8c. Amussiinn cancellatum, n. sp., ..... 315

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PLATE XXIV

Figs. 1-la. Amussiurn mericUonale, n. sp..

Figs. 2-2c. Amitssivm lucidum, Jeffreys,

Figs. 3-3«. Lima lata, n. sp., .

Figs. 4-4fl. Lima tahitcnsis, n. sp.,

Figs. 5-5a. Lima (Limatula) torresiaria. n. sp..
Figs. 6-6a. Lima (Limatula) confusa, n. sp.,

Figs. 7-7a. Lima {Limatula) laminifera, n. sp..

Figs. 8-8?^. Necera kerguelenensis, n. sp..

PAGE

316

317
287
289
291
292
293
46

The Voyage of H.MS "Challenger"

. Pinu

PLATE XXV.

(ZdOI.. CHAI.L. ESP. — PAUT xxxv. — ^1885.) — Mm

PLATE XXV.

Figs. 1-16.
Figs. 2-2/>.
Figs. 3-36.

Figs. 4-46.

Figs. 5-0 6.

Figs. (5-(j6.
Figs. 7-76.
Figs. 8-86.
Figs. 9-96.

Liioihfii'Ua jeffveysi , u. sp., .

Lj/onsiella pcqyyracea, n. sp.,

Lyomidla gmndis, n. sp., .

Silenia sarsii, u. sp..

Ervilia sandwichensis, u. sp.,
Verticordia australiensis, u. sp. ,
Verticordia woodii, n. sp., .
Verticordia quadrat a, n. sp.,
Verticordia tornata, Jeffreys,

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THE

VOYAGE OF H.M.S. CHALLENGEK.

ZOOLOGY.

REPORT on the Gephyrea collected by H.M.S. Challenger during the Years
1873-76. By Dr. Emil Selenka, Professor in the University of

Erlangen.

INTRODUCTION.

Among the Gephyrea collected during the Challenger Expedition, many diifercnt genera
are represented, but the number of species is comparatively small. The twenty-eight
species to be afterwards discussed are distributed over eleven genera, and these
already known. Two of these genera were indeed described as new by the late R.
von Willemoes-Suhm in his letters published in the Zeitschrift fiir wissenschaftliche
Zoologie and in his manuscript notes. But an examination of the original specimens
has shown that one of these is really a Bonellia, and the other, designated Leioderma,
n. gen., by v. Willemoes-Suhm, a true Phymosoma. The latter species, along with some
other more or less damaged specimens, must, moreover, be excluded from our description,
since their state of preservation was not such as to admit of an accurate diagnosis of
their specific characters. None of them, however, exhibited any important peculiarities.

The habitat and distribution of some of the species are of special interest. Some
forms which had previously been found only near the shore, were on the Challenger
Expedition dredged from very considerable depths. One new deep-sea species was foimd
in the Pacific and also in the North Atlantic Ocean, and in regard to other forms the
range of distribution was shown to be much wider than had hitherto been recognised.

If one may venture to draw general conclusions from the scanty matei-ial at our
disposal, it appears probable that the tube-inhabiting Gephyrea (genus Phascolion and
many species of Phascolosoma) occur especially in the greater depths, where as yet there
has been found only a single example of the free-living forms of the genus Phymosoma.

(ZOOL. CHALL. EXP. — PART XXXVI. — 1885.) Nn 1

•2 THE VOYAGE OF H.M.S. CHALLENGER.

Tliis difference in tlic distribution of those allied genera seems to be associated with
dilierences in temperature. The eighteen known species of Pkymosoma are almost
exclusively tropical or subtropical forms,^ occurring only at moderate depths or near
shore, and therefore in water comparatively warm. Now, since the temperature of the
deep sea is on the whole strikingly low, the almost total absence of forms of Phymosoma
in these depths may l^e conditioned by the lack of the requisite warmth. On the other
hand, the great majority of the tube-inhabiting forms belonging to the genera Phasco-
losoma and Phascolion were found in the waters of the temperate and cold zones, and in
the deep sea, while several species of the same genera are also tropical.

In describing the various species I have given references to the more important
literature of the subject. In regard especially to the Gephyrea achceta, I would mention
my recent monograph on the Sipunculi.'^

Sy7topsis of the Genera and Species.

A. Gephyrea ch^tifera.

Genus 1. Steniaspis, Otto.

1. Sternaspis princeps, n. sp.

Genus 2. EcMurus, Gueriu.

2. Echiurus unicinchis, v. Drasche.

Genus 3. ThaJassema, Gaertner.

3. Thalassema faex, n. sp.

4. Thalassema haronii, Greeff.

Genus 4. BoneUia, Rolando.

5. BoneUia suhmii, n. sp.

B. Gephyrea ach^ta.

Genus 5. Phascolosoma, F. S. Leuckart (s. str. Selenka and de Man),
(a) Proboscis with four retractors. Hooks present.

6. Phascolosoma vtdgare, de Blainville.

7. Phascolosoma vidgare, var. astiita, nov.

8. Phascolosoma pudicum, u. sp.

1 We have an exception in tlie Plujmosoma granulatum of tlie Meiliterranean, wliicli is most closely allied to the
Phymosoma scolops of the Red Sea and Pacific and Indian Oceans, and which has doubtless found its way from the Red
Sea into the Mediterranean.

2 Die Ripunculiden, eine systematische Monographic, nnter Mitwirkung von Dr. J. G. de Man and Dr. C. Biilow
hearbeitet vnn Dr. Erail Selenka; in Semper's Reisen im Archipel der Philippinen, Theil. II. Bd. iv. Abth. 1, also
separately, Wiesbaden, 1883.

REPORT ON THE GEPHYREA.

(b) Proboscis with four retractors. Hooks absent.

9. Phascolosoma capense, Teuscher.

10. Phascolosoma prioki, Sluiter.

11. Phascolosoma catharincB, Fritz Mliller.

12. Phascolosoma jiagr if erum, n. .sp.

Genus 6. Dendrostoma, Grube.

13. Dendrostoma hlandum, Selenka and de Man.

Genus 7. Phascolion, Theel (Selenka and de Man).

14. Phascolion sqiiamatum, Koren and Danielssen.

15. Phascolion Intense, n. sp.

16. Phascolion tubicola, Verrill.

17. Phascolion hotulus, n. sp.

18. Phascolion stromhi (Montagu).

Genus 8. Aspidosiphon, Grube.

19. Aspidosiphon specidator, n. sp.

20. Aspidosiphon truncatus, Keferstein.

Genus 9. Phymosoma, Quatrefages (Selenka and de Man).

21. Phymosoma japonicum, Grube.

22. Phymosoma scolops, Selenka and de Man.

Genus 10. Sipunculus, Linne.

23. Sipunculus nudus, Linne.

O. Appendix.

Genus 11. Chcetoderma, Loven.

24. Chcetoderma militare, n. sp.

DESCRIPTIOxN OF GENERA AND SPECIES.

Order GEPHYREA.

Auuelids with degenerated segmentation, without external jointing, without para-
podia, and without dorsal gills. There is a closed vascular system, and one to three
(rarely six) pairs of segmental organs. There are seldom numerous setfe, and in most
species none. The sexes are separate. Found in all seas.

A. Gephyeea ch^tifera.
Gephyrea ivith setcB.

Genus 1. Sternaspi's, Utro.

The body is indistinctly segmented, and there are bundles of seise both anteriorly
and posteriorly. The ventral surface is smooth, and at the posterior end there is a .shield,
the borders of which are provided with setaj. The anterior end of the body bears a long
forked proboscis. Anus at the posterior end, and lieside it numerous retractile gill-
filaments (Kiemenfaden). Found in all seas.

Since Sluiter found a long forked proboscis in the East Indian Sternaspis spinosa,
Sluiter, we are probably justified in assuming the presence of a similar proboscis in the
other species of the genus, although it has as yet been observed only in that one.
Sluiter himself reports, indeed, that the proboscis is always thro-mi off by the animal a
few minutes after its capture.

It does not seem to be beyond question whether the form preserved in the Challenger
collection can be regarded as really the representative of a distinct species. All the
species of Sternaspis as yet knovvTi are very like one anothei", and our Sternaspis princeps
is only distinguished by subordinate characters, on the one hand from Sternaspis
spinosa, Sluiter, from Batavia, and on the other from the Sternaspis costata of Mareu-
zeller, from the Bay of Aliya. The imperfect preservation of the Challenger specimen
unfortunately does not admit of any intimate description of the anatomical structure.

6 THE VOYAGE OF H.M.S. CHALLENGER.

1. Sternaspis princeps, n. sp. (PI. I. fig. 1).

Alono- the middle of the ventral surface there runs a shallow furrow, and each half i.s
divided by a diagonal keel into an anterior larger and a posterior smaller triangle.
There are forty tufts of setae on the margin of the shield. The whole body is studded
witli fine scattered chitinous setae, each having at its base a number of smaller chitinous
pieces grouped together into a small wart-like protuberance.

Of the two specimens preserved the larger is represented in fig. 1.

HaUtat— Station 169, July 10, 1874; lat. 37° 34' S., long. 179° 22' E. ; depth,
700 fathoms ; bottom temperature, 40° "0 ; blue mud ; trawled.

Genus 2. Echiurus, Guerin.

The proboscis has a deep furrow, but is not sjalit in front. There are two anterior
ventral hooked setae, and one or two circles of posterior bristles. Two pairs of segmental
organs, two internal anal vesicles (Analkiemen) with ciliated funnels.

2. Echiurus unicinctus, von Drasche (PI. I. fig. 2; PI. III. figs. 11, 12).

Echiunig unicincfus, von Drasche, Ueber eine neue Echiurus-ATt aus Japan, &c., Verliandl.
d. k. k. zool.-'bot. Gesellscb. Witii, BJ. xxx. pp. 621-628, Taf. xxx. fig. 1, Jahrg.
1880, 1881.

Short proboscis. There is only one circle of j)Osterior bristles. The paired
appendages of the segmental organs are long and spirally coiled.

Out of twenty-one specimens the average length was 7 cm. and the breadth about
15 mm. The largest was 9|- cm. lojig. All were much contracted. The grooved
proboscis is not very sharj^ly distinguished from the body, it has a conical form and is
very short, not exceeding 6 mm. in its contracted state. The papillae on the skin
measure from 0'2 to 0"5 mm., and look like numerous little knots. They are not
arranged in transverse rows except at special places, as for example close beside the
ventral setai. The preserved specimens are of a bright yellowish- brown colour.
Immediately behind the base of the proboscis on either side of the median ventral line
are the two moderately strong hooked setae. At the posterior end of the body there is an
anal region bordered by a single circle of golden stylet-like setae, bent slightlj' outwards.
In most of the specimens there were eleven of these setae, but in some nine, ten, twelve.
or thirteen. As in the other species of Echiurus, the circle of setae exhibited a distinct
gap on the ventral surface. Here and there reserve setae may be seen. In regard to the
musculature, it may be noted that the internal layer of circular muscles consists of nl)out

REPORT ON THE GEPHYREA. 7

two hundred luindw repeatedly anastomosing. The alimentary eanal r-onsists of n pharvTix,
a narrow muscular oesophagus, an intestine with three main loops, wliicli after forming a
small cfecum is continued into a wide rectum terminating in the cloaca. Ivich loop
of the intestine is attached to the body-wall by special muscles, which frequently broaden
out into a fan-shape as they approach the intestine. The strands attaching the rectum
(" Befestiger") are especially numerous (sixty to seventy). As regards the vascular
system, two vessels admit of ready recognition, one dorsal accompanying the alimentary
canal, and one ventral Ipng above the nerve-cord. Like v. Drasche I was unable to
discover any trace of a vascular ring. Both pairs of segmental organs have associated
with them near their external opening two spirally coiled appendages like those wliicli
occur in most species of Tlialassema, where Greeff has described them under the
designation " .spiral tubes." They are also described and figured by v. Drasche. The
anal vesicles are in structure like those of Echinrus pallasii.

Some of the specimens were so well preserved that a detailed representation of the
ciliated funnels was in some cases possible (PL III. figs. 11, 12).

Habitat. — Inland Sea, Japan. From fishermen, May 28, 1875.

Von Drasche notes that in both the specimens which he examined the proboscifs
(Kopflappen) was wanting. Careful investigation, however, has convinced me that the
short process at the anterior end of the body really represents the whole proboscis. It is
quite likely then that even in von Drasche's specimens the proboscis was present and
complete.

This species was first mentioned by Willemoes-Suhm * in the following terms : —
"A new Echiurid from the Japanese coast, used by the fishermen as bait, and occurring
in the mud close by the shore. The worm measured 3 to 4 inches in length, and in
all its characters resembled the genus Echinrus except in having a single posterior circle
of setae instead of two."

Genus 3. Tlialassema, Gacrtner.

Body swollen with a short undivided proboscis. Two internal anal vesicles, usually
with ciliated funnels. Only two anterior ventral hooked seta?. There are one to six
pairs of (anterior) segmental organs.

3. Thalassemafaex, n. sp. (PI. III. fig. 13).

The longitudinal musculature is undivided. There is only a single pair of segmental
organs. The proboscis is small. The thin skin of the preserved specimen is whitish and
smooth, the papillae are indistinct and scattered. The intestine exhibits the usual charac-

' Brief VII. an C. Th. von SieboKl, Zeitschr. f. niss. Zooh, Bd. xxvii. p. cii., 1876.

8 THE VOYAGE OF H.M.S. CHALLENGER.

teristics. The oiial vesicles arc of moderate size, with irregularly distributed csecal
appendages, some of which are simple and others much branched, and which seem
usually to l)ear at their apex only a single minute ciliated funnel. In front of the
external openings of the segmental organs are two small hooked sette. There is only
a single i)air of segmental organs, which have at their extremity a folded and Avrinkled
vesicle.

There was only a single contracted specimen about 40 mm. long and 15 mm.
broad.

Habitat.— ll.M.i>. "Porcupine," Station 77, 1869; lat. 60° 34' N., long. 4° 40' E.;
560 fathoms.

In some other species, namely in Thalassema mobii, GreefF,^ and Thalassema vegrande,
Lampert," the longitudinal musculature consists, as in this case, not of a number of
separate strands, Ijut of a continuous sheath. These two species above mentioned,
however, possess three pairs of segmental organs, and are therefore readily tlistiuguishable
from Thalassema facx. A single pair of segmental organs is characteristic only of
the latter and of Thalassema gigas, Max Miiller, which was found at Trieste, and is not
identical with this species.

4. Thalassema haronii, Greeff.

Thalassema haronii, Greeff, Die Ecliiuren (Gephyrea armata), Nova Acta Acad. Caes. Leop.-
Carol., Bd. xli. pars ii., No. 1, pp. 151, 152, Taf. vi. figs. 63, 64, 1880.

Owing to the imperfect preservation of the single specimen, only a very incomplete
examination of the internal organs was possible. The proboscis was torn away. Greeff
found the species at Arrecife on the Canary Island Lanzerote, near the shore, among lava
blocks and debris. Of the real colour of Thalassema haronii, which GreeflF describes as
dark green with longitudinal stripes of xiolet, there was no longer any trace in the
yeUowish-brown specimen of the Challenger Exjaedition. On the other hand, however,
the two forms, found in such different places, agree in the following characters.

The whole body is covered with small papillse. Each of the two pairs of segmental
organs has at its extremity a funnel. The anal vesicles have the form of two long tubes,
bearing on their surface short tree-like branches, which to the naked eye look Uke tufts,
and which possess terminal ciliated funnels. The longitudinal musculature of the body-
waU is arranged in from twenty to twenty-three strands.

Habitat.- — Bahia, September 1873, 7 to 20 fathoms.

The anatomical structure of the Challenger specimen so closely resembles that of
Greeff's species that I have no hesitation in identifying the two forms.

' R. Greeff, Die Echiuren (Gepbyrea armata), Nova Ada Acad. Caes. Leop.-Carol., Bd. xli. pars ii.. No. 1,
p. 152, 1880.

- K. Lampert, Ueber einige neue Thalassemen, Zdtaclw.f. wiss. ZooL, Bd. xxxix. p. 341.

REPORT ON THE GEPHYREA. 9

Genus 4. Bonellla, Eolaudo.

Body swolleu. Proboscis much elongated and forked at the apex. There are
only two anterior hooked setae. Two internal anal vesicles with ciliated funnels ; only a
single anterior segmental organ (the uterus). The male is Planarian-likc, without mouth
or anus.

5. BoneUia suhinii, n. sp. (PI. 1. fig. 3; PI. II. figs. 4-G).

In fig. 3 is reproduced the original sketch of Willemoes-Suhm. His manuscript
notes on the internal structure of this form are not quite correct. He erred by mistaking
mouth for anus, and vice versa.

Anatomical investigation has demonstrated that this form, which was described in
V. Willemoes-Suhm's notes as a new genus, is really a true BoneUia. It must be confessed
that both the posterior end of the body and the proboscis were torn away from the
specimen, that the hooked sette were not to be found, that the intestine was only partially
present, and, in general, that the internal organs were much injured and torn. Yet from
the following description it will be seen that we have here undoubtedly to do with a true
BoneUia.

Fig. 3 on PI. I. displays the single specimen in its natural size. The dermal muscular
sheath was for the most part relaxed anteriorly, and much contracted posteriorly.
Over this posterior portion the external skin seemed to be covered by irregularly
distributed warts. Of the internal organs the following were preserved (PI. II. fig. 4) :
— the anterior portion of the alimentary canal (torn away at y), the oesophageal nerve-
ring and ventral cord (n), the uterus {u), with its ciliated funnel, and the two anal
vesicles (2, 2), of which the anterior portion is slightly enlarged in fig. 6.

The uterus (fig. 5) was filled with aljout sixty eggs, which exhibited the characteristic
structure of the ripe eggs of the Mediterranean BoneUia. The male was not to lie seen
either in the oesophagus or in the uterus.

Habitat— Station 47, May 7, 1873; lat. 41° 14' N., long. 65! 45' W.; depth, 1340
fathoms, off Nova Scotia ; blue mud ; dredged.

1 have taken this opportunity of giving a figure of the male BoneUia viridis, Rolando,
more complete than hitherto (see PI. II. figs. 7-10).

The males of BoneUia were, as is well knowm, first described by A. Kowalevskv ' as
Planarian-like parasites in the uterine portion of the female genital duct.

The discovery of the Russian embryologist was confirmed by Catta and Marion,- and

' A. Kowalevsky, Schriften d. naturf. Gesellsch. zu Kiew, Bd. v., and also in a French translation under the title Du
male planariforme de la Bonellie, lievue des Sci. Nat., t. iv., Xo. 8, pp. 313-319, pi. vii., 1875.

2 Ibid.

(ZOOL. CHALL. E.XP. PART XXXVI. — 188-5.) Nn

10 THE VOYAGE OF H.M.S. CHALLENGER.

the latter noted on the minute male the presence of two hooks behind the mouth opening.
Vejdovsky ^ investigated anew the structure of the male Bonellia, and discovered the
central nerve-cord, which had till then been overlooked. I then ^ described for the first
time the oesophageal nerve-ring, the alimentary canal without mouth or anus, and the
two rudiments of the anal vesicles. In a very exhaustive memoir Spengel ^ has given
figures and desci'iption of the structure of the male BoneUia, yet both this naturalist and
Greefi" have overlooked the rudimentary anal vesicles which I have here figured in
PL II. fig. 10. After Spengel's excellent description it seems to me unnecessary to
enter further into the discussion of the anatomical details, and I therefore simply refer to
the fio'ures.

B. Gephyeea ach.5;ta.

A. Gepliyrea without seta;.

Genus 5. Phascolosoma, F. S. Leuckart.

"The longitudinal musculature is continuous and not divided into distinct bands.
There are numerous tentacles arranged in a circle or in groups round al;)out the mouth.
The intestine is spirally coiled. The " intestinal spiral " (Darmspira) in the posterior
portion of the body quite unattached. Hooks may be absent. There are two
free segmental organs. Eggs spherical. Two to four retractors of the proboscis.
Found in aU seas.

G. Phascolosoma vulgare* de Blainville.

Sipunculus vulgaris, de Blainville, Diet. d. Sci. Nat., t. xlix., 1827, pp. 312, 313, Vers.,

pi. xxxiii. fig. 3.
Sijrinx harveyi, Forbes, A History of British Starfishes, London, 1841, p. 249, with woodcut.
Phascolosoma vidgare, Keferstein, Beitrage zur Kenntniss der Gattung Phascolosoma, F. S.

Leuckart, Zeitschr. f. wiss. Zool., Bd. xii. p. 39, Taf. iii. tig. 3, 1862 ; Ibid., Bd. xv.

p. 429, Taf. xxxi. fig. 5, 1865.
Phascniosnma murgaritaccum, Keferstein, Beitrage zur anatomischen iind sj'stematischen Kenntniss

der Sipunculiden, Zeitschr. f. wiss. Zool., Bd. xv. p. 530, Taf. xxxi. fig. 9, Taf. xxxii.

figs. 28, 29, 1865.

1 F. Vejdovsky, Ueber die Eibildung und Manncben von Bonellia viridis, Eol., Zeitachr. f. u-isn. Zool., Bd. xxx.
pp. 487-500, pi. XXX., 1878.

2 Em. Selenka, Das Manncben d. Bonellia, Zool. Anzeiger, No. C, p. 120, 1878.

' G. W. Spengel, Beitrage zur Kenntniss der Gephyreen, I. Die Eibildung, die Entwickehing und das Mannchen
der BoneUia, Mitteilungen aus der Zoolog. Station %u Neapel, Bd. i. Heft. iii. Taf. viii.-xii., 1879.

* Strictly speaking the setae are not always absent. In the young larva of Pliascolosoma vulgare, for instance, I
found three pairs of setae. These are, however, subsequently thrown off. In the adidt animals true setae seem to be
entirely absent. Vide Eifurchung und Larvenbildung von Phascolosoma elongatum, Zeitschr. f. wiss. Zool, Bd. xxv.
p. 446, Taf. XXX. fig.s. 14, 15, 18, 1875.

REPORT ON THE GEPHYREA. 11

Sipuncuhis obscunis, Quatrefages, Histoire naturelle dcs Annel^s marins et d'eau doiico, t. ii.
p. 216, pi. xvi. figs. 16, 17, 1865.

Phuscoloaoma validuiii, Th6el, Etudes sur les Gcpb^Ticns inermes dcs mors de la Scaiidiiiavio, du
Spitzberg efc du Groenland, Bihang til k. Svenska Vet. Akad. Handl., Bd. iii., No. 6, Stock-
holm, pp. 7, 8, pi. i. fig. 5, pi. iii. fig. 18, pi. iv. Hg. 20, 1875.

Phascolosonia luteurn, Th(5el, Ibid., p. 5, pi. ii. fig. 7, pi. iii. fig. 17.

Phascoloscmia harveiji, Koren and Danielssen, Fauna littoralis Norvegise, Heft, iii., Bergen, p. 136,
Tab. XV. figs. 41, 42, 1877.

Phascolosoma vulgare, Selenka and do Man, Die Sipunculiden, &c. {loc. cit.), pp. 20-23, Taf. i.
fig. 1, Taf. iii. figs. 25-34, 1883.

The body is nearly 100 mm. long, the slender proboscis measures about the same.
The thin skin is smooth except at the posterior extremity and at the base of the proboscis
where there are numerous cylindrical papillae, measuring up to 0'1.3 mm. in height, and
becoming gradually smaller towards the mouth. There are about thirty-six tentacles,
which are heart-shaped in cross section. The hooks are scattered, of irregular shape,
mostly somewhat bent, and about 0'15 mm. long. Three fixing intestinal muscles,
inserted on the gullet, on one of the first coils, and on the rectum. The proboscis has
four retractor muscles. Those which are ventral spring from the anterior portion of the
median third of the 1)ody, while those which are dorsal arise between the former and
the anus.

Habitat.— RM.'^. "Porcupine," Station 30, August 2, 1870; lat. 36° 15' N.,
long. 6" 52' W. ; depth, 386 fathoms : and Station 90, 1869 ; lat. 59° 41' N., long. 7° 34' E. ;
depth, 458 fathoms. This latter form might be considered as a variety of the ordinaiy
Phascolosoma vulgare. Hitherto this species has been found in the Mediterranean, on
the west coast of Europe (St. Vaast la Hongue, St. Malo, Koscofi", Bergen, North Sea),
on the English coast, and in the Eed Sea.

7. Phascolosoma vulgare, var. astiita, nov.

This variety, above referred to, difiers from the typical form in having the whole bod}'
studded with papillas, and not merely the anterior and posterior portions.

8. Phascolosoma pudic urn, n. sp. (PI. III. figs. 14-16).

This species bears a most marked resemblance to the Phascolosoma vulgare of
de Blainville, both in habit and in anatomical structure, but is distinguished both
from it and from the Phascolosoma vulgare asttitum by the following charactera : — the
hooks are not scattered, but are arranged in distinct rows, the papilla3 cover the
whole body including the proboscis, the tentacles are less numerous (1 counted at most
twenty).

12 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat. — (a) Kerguelen, January 21, 1874, Cape Maclear ; 30 fathoms (three
specimens).
(6) Kerguelen, Station 149h, January 29, 1874, Cumberknd Bay ; 127

fathoms (numerous specimens),
(c) Kerguelen, 10 to 100 fathoms (one specimen).
The largest specimen measured in its extended state 3(5 mm., including the proboscis.

B. Four Retractor Muscles. Nq^ Hooks on the Proboscis.^ '

9. Phascolosoma capense, Teuscher.

Phascolosnma capense, Teuscher, Notiz iiber Sipimculus nnd Phascolosoma, .Jenaische Zeitschr.

f. Naturwiss., Jena, Bd. viii. pp. 498, 499, Taf. xix. figs. 4.^, 12 and 14, 1884.
Phasenlosovia capense, Seleuka and de Man, Die Sipunculiden, &c. {loc. eit.), pp. 29, 30, Taf. iii.

ligs. 40-43, 1883.

Of this species a great number of specimens are preserved ; they vary from 20 to
35 mm. in length, not including the proboscis.

The body is four to eight times as long as it is broad. The proljoscis measures about
three-cpiarters of the length of the body. The skin is firm and somewhat shining. Even
with the unaided eye one can recognise the numerous dark papillae, which attain a height
of 0"1 mm., and cover both the body and the proboscis. The ventral retractors of the
proboscis spring from the middle third of the body, while those which are dorsal are at
some distance from these, and spring from the anterior third. On the oesophagus there
lies a long contractile tube bearing villi. The twisted intestine has about twenty double
coils, and there is only a short anterior spindle-shaped muscle. There are three fixing
muscles for the intestine.

Habitat. — Sea Point, near Cape Town ; shallow water. November 1873.

C. Two Retractors. No Hooks on the Proboscis.

10. Phascolosoma jyrioki, Sluiter.

Phascolosoma prioJii, Sluiter, Beitriige zur Kenntniss der Gepliyreen aus dem Malayischen
Archipel, Natuurkundig Tijdschrift van Nederlandsch Indie, Bd. xli. p. 1.52, Taf. i.
figs. 5-9, Batavia, 1881.

Skin thin and smooth, without papillse. The body is rather long and narrow, and the
proboscis is longer than the body. The two retractors of the proboscis have their origin
far back in the body. The spindle-shaped muscle is but slightly developed, but there
are numerous muscles fixing the intestine.

' The presence or absence of these prohoscal hooks is a distinctive character for most of the species of the genera —
Phascolosoma, Phymosoma, and Phascolion. But since the hooka sometimes fall off entirely, too niucli stress must not
be laid upon this specific difference. In no case, however, is the presence or absence of hooks on the proboscis a
distinction between "cnera.

REPORT ON THE GEPHYREA. 13

On anatomical examination the minute specimen (13 mm.) of tli(! Challenger Expedi-
tion was, seen to be identical with the Phascolosoma priohi of Sluiter.

Habitat.— ^taimu 214, on February 10, 1875; lat. 4° 33' K, long. 127° 6' E.; depth,
500 fathoms; bottom temperature, 41°'8 ; blue mud; dredged.

Sluiter obtained his specimens from Dentalium shells at Tandjong Priok, Batavia. In
regard to the specimen above referred to, there is no note as to whether it also was
obtained from a Mollusc shell.

11. Phascolosoma catharinw, Fritz Miiller.

Phascolosoma catharinie, Fritz Miiller ; Grube, Notiz iiber Loxosiphon, Oloeosiphon und einige

Phascolosomen, Jahresbericht der Scliles. Gesellsch. fiir vaterl. Ciiltiir, Jahr 1867, p. 48,
Breslau, 1808.

Phascolosoma catharinm, Selenka and de Man, Die Sipuncididen, &c. (loc. cit.), pp. I.t, 16,

Taf. ii. fig. 16, Taf. v. figs. 60-63, 1883.

The body is long and narrow, with a slender proboscis four times as long as the body.
The skin is thin and iridescent. Only with the aid of a lens can one recognise the
minute papillte which cover the whole body. These papillae are thinly scattered and
have a conical form. At the posterior end of the body they measure 0"066 mm. in height
and half as much in breadth, at the middle of the body they are somewhat smaller, and at
the base of the proboscis somewhat larger again {up to 0"09 mm. in height). There are two
slender ventral retractors, which originate in the posterior fourth part of the body, and
which do not unite till far forward in the proboscis. The contractile tube is studded with
short villi. The coils of the intestine are not numerous. There are two fixing muscles on
the anterior coils. The two free segmental organs open a short distance in front of the anus.

Hahitat.— Station 323, February 28, 1876; lat. 35° 39' S., long. 50° 47' W.; depth,
1900 fathoms ; bottom temperature, 33°-l ; blue mud ; trawled. Of this there is only a
single specimen.

Since Fritz Miiller's specimen was labelled "Desterro," one may infer that it was not
obtained in trawling, but was found on the shore during ebb tide. The specimen of the
Challenger Expedition, on the other hand, was obtained from a very considerable depth.
This difference of distribution is not, however, by any means unicjue, for other true
Sipunculids exhibit a similar occurrence on the shore and at considerable depths.

12. Phascolosoma flagrifeyum, n. sp. (PI. III. fig. 17).

Body and proboscis studded with very small papilla?, hardly visible witli a lens. The
•posterior end of the body is furnished with wart-like papilku measuring half a millimetre,
and with a whip-like appendage. The coils of the intestine are veiy numerous.

The largest of the three specimens of this form measured with outstretched proboscis
was 130 mm. in length, and had a breadth of about 13 mm.

14 THE VOYAGE OF H.M.S. CHALLENGER,

The two retractors of the proboscis spring from about the middle of the body ; after
a short course they run together. The looped intestine has seventy coils or more, and
is free posteriorly. In front, attached to the oesophagus, there is a long fixing muscle.
There is also a spindle-shaped muscle. There are two segmental organs, entirely free, and
opening beside the anus. Hooks are absent. Round about the mouth there is a circle of
finger-like tentacles, heart-shaped in cross section. There is a simple contractile tube.
The body-wall is rather thin but elastic.

In the Challenger collection there are two well-preserved specimens from the Pacific,
and another single specimen from the east coast of North America. In S2)ite of this
very wide diflerence in distribution, a close comparison revealed no structural difi'erence
worth recording.

Habitat.— (a) Station 241, June 23, 1875 ; lat. 35° 41' N., long. 157° 42'- E.; depth,
2300 fathoms ; bottom temperature, 35°"1 ; red clay ; trawled (two
specimens).
(b) Station 44, May 2, 1873; lat. 37° 25' N., long. 71° 40' W.; depth,
1700 fathoms; bottom temperature, 36° "2 ; blue mud; dredged
(one specimen).

Genus 6. Dendrostoma, Grube.

Longitudinal musculature continuous and not divided into separate bands. The
tentacles are united into four to six bundles. There are two free segmental organs,
intestine spirally coiled, the intestinal spiral free posteriorly. Hooks present except
when they have fallen ofi". Short, compressed, tropical, shore forms.

13. Dendrostoma hlandum, Selenka and de Man.

Dendrostoma hlandum^ Selenka and de Man, Die Sipunculiden, &c. {loc. cU.), pp. 85, 86,
Taf. i. fig. 9, Taf. xi. figs. 159-162, 1873.

Body swollen. Proboscis rather short. Skin brownish, of moderate thickness. Un
the middle of the proboscis is a zone of numerous, scattered, pointed, black hooks,
0*4 mm. in height, and therefore distinctly noticeable even to the naked eye. The whole
body is studded with small scattered papillae with a circular base. The tentacles are
arranged in five (to six) main bundles. There are two powerful ventral retractors of the
proboscis which have their origin in the median third of the body. Two segmental
organs completely free. The contractile tube is destitute of villi.

Habitat — Yokohama (Japan); depth, 5 to 25 fathoms. May 6, 1875.

The only specimen obtained was found in the same place as those which have been
previously recorded, namely, on the coast of Japan. Dr. HUgendorf found the animal at
a depth of 4 fathoms.

REPORT ON THE GEPHYREA. . 15

Genus 7. Phascolion, Theel (Selenkn aud de j\Iau).

The animals of this genus live in tubes or in shells of Molluscs. The longitudinal
musculatui'e is continuous and not divided up into distinct bands. The tentacles are smaJl
and finger-like, and are arranged in a circle round about the mouth. There is only a
single, fixed segmental organ. The intestine has only a few coils, or it may be none at all,
but there are always some large loops which are attached by the so-called fixing muscles.
The hooks of the proboscis often fall ofi" at an early stage. The proboscis has either one
or two retractor muscles. The posterior half of the body frequently with attaching papillae
{Haftpapillen). They are found in all seas, but especially in the colder waters.

It seems extremely probable that the species of the genus Phascolion do not form a
compact, closely related group, but that they have developed independently from various
true Phascolosomata. One marked characteristic of the species of Phascolion is the dis-
appearance of one of the two segmental organs. Noteworthy also is the shortening of
the intestine, associated with the assumption of the looped instead of the spirally coiled
form. Now since all the species of Phascolion live in Mollusc tubes, the change of habitat
must have reacted on the anatomical structure ; it may, for instance, have to do with
the degeneration of one of the segmental organs, and it may be that the burden of the
shell has brought about the early attachment of the intestine by means of the fixing
muscles. The fact that in many species of Phascolosoma, which inhabit Mollusc shells or
tubes, one of the segmental organs is often absent but the coiled intestine apparently
not shortened, shows us how such a degeneration as that of the species of Phascolion has
arisen. In the latter, as we have mentioned, the spirally coiled intestine is unwound
into loose loops, and there are transitional states between the two conditions.

If the supposition be correct that the species of the genus Phascolion are connected with
those of the genus Phascolosoma by diverse lines of origin, the genus Phascolion should
be resolvable into several, since the system ought to be the expression of phjdogenetic
relationship or genetic history. But since it is not possible to recognise these genetic
relationships, far less prove them, I therefore retain for the present the single genus
Phascolion.

14. Phascolion squamatum, Koren and Danielssen (PL IV. figs. 18-19).

Fhascolosomasquamatum, Koren and Danielssen, Fauna littoralis norvegiae, Heft iii pp. 130, 131,

Tab. xiii. fig. 11, Tab. xiv. figs. 14, 15.
Phascolosoma squamatum, Selenka and de Man, Die Sipunculiden, &c. (loc. cit.), p. 40.

The body is four times as long as it is broad. The proboscis is two and a half timas
as long as the body. The skin is studded all over with large, flat, more or less protrusive
scales. On the proboscis are fine papillae, arranged in separate rows and at a distance
from one another, but somewhat more closely set near the tentacles. The tentacles are

16 THE VOYAGE OF H.M.S. CHALLENGER.

.sliort and thread-like. There is only one retractor muscle, which has four very short
roots inserted at the hind end of the body. The intestine exhibits five loose loops in the
right half of the body, and then passes into the close spiral with sometimes twelve double
coils. A thin contractile tube. Only one segmental organ, on the left side of the body.
The body is not more than 1 1 mm. in length.

Habitat.— (a) H.M.S. " Porcupine," Station 6, 1870 ; lat. 48° 26' N., long. 9° 44' W. ;
358 fathoms.

(b) H.M.S. "Porcupine," Station 47, 1869 ; lat. 59° 34' N., long. 7° 18' W.;

542 fathoms.

725 fathoms.
(c/) H.M.S. "Triton," Station 10, August 24, 1882; lat. 59° 40' N.,
long. 7° 21' W.; 516 fathoms.

The intestine contained numerous Globigerina shells, besides sand and fine debris of
mussel-shells and of the calcareous plates of Echiuodermata.

This species occupies a position only just within the genus Phascolion, being indeed
a sort of connecting link with the genus Phascolosoma. It may be ranked as a species
of Phascolion on account of ( 1 ) the disappearance of one of the two segmental organs
and the fixing of the remaining one by means of a mesentery, (2) the coalescence of the
retractors of the proboscis and the shifting of their insertion to the hind end of the bodj^,
(3) the smaller size of the testacies, (4) the larger size of the eggs, (5) the development of
the ordinary dermal papillse into attaching papillae, (6) the partial unwinding of the intes-
tinal spiral into loose coils. On the other hand, since the intestinal spiral may still have
as many as twelve double coils, the species may be claimed, as Koren and Danielssen
have done, for the genus Phascolosoma. On the whole, however, there seems more
reason, as we have indicated, to refer the species to the genus Phascolion.

15. Phascolion Intense,^ n. sp. (PL IV. figs. 22, 23).

The skin is thin and without attaching papillae (Haftpapilleu) on the posterior part
of the body. The whole body and proboscis studded with numerous scattered skin glands.
These protrude as slight tubercles, and are supported by chitinous borders, which appear
circular or elliptical according to the state of contraction of the cutaneous muscles. The
diameter of these glands measures about one-third of a millimetre, but in the region about
the base of the proboscis and about the anus the diameter is reduced by one-half or even
much more. On the proboscis and on the posterior extremity of the body the glands
bear villous-like bodies round their opening (HohlpapiUen). These papilte are about

' Lutends, living in the nmd.

KEPORT ON THE GEPHYKEA. 17

0"08 mm. long hy 0'02o mm. lu'oacl ; on other part.s of the l)o(ly tliey are wholl)- alisent.
There is only one retractor to the proboscis. The intestinal spiral has about twenty-three
coUs. The animal makes tubes in the mud.

Two of the three specimens were examined. The length of the largest was 30 mm.,
with proboscis wholly retracted. The thin transparent skin of tlic body was not
coloured, the zone round about tlie anus was light brown.

'Hooks on the proboscis absent. The tentacles are short and small. As in the other
species of PhascoUon, the tentacles are few in number, at most sixteen. The single
retractor of the proboscis originates just in front of the hind end of the l)ody, and
possesses several diverging roots. Far back in tlie body, where the (esophagus passes
into the intestine, the latter is attached by one fixing muscle. There are, however, some
other fixing muscles on the threefold loops of the intestine and on the rectum.

The single segmental organ is on the right side of the body. It lies close beliind the
anus, and is throughout its whole length bound by connective tissue bands to the inner
body-wall.

This species is distinctly characterised by the large number of intestinal coils ami by
the nature of the skin glands.

Hahitaf. — The animals were found in two localities near one another.

(a) Station 157, March 3, 1874; lat. 53° 55' S., long. 108° 35' E. ; depth,

1950 fathoms ; Diatom ooze ; bottom temperature, 32°"1 ; trawled. (Two

specimens with thick mud tubes.)

{!>) Station 156, February 26, 1874 ; lat. 62° 26' S., long. 95° 44' E. ; depth, 1975

fathoms; Diatom ooze; trawled. (One specimen and several mud tubes.)

16. PhascoUon tubicola, Verrill.

PhascoUon tubicola, Verrill, Kesults of Recent Dredging Expeditions on the Coast of Xew
England, Anier. Journ. Sci. and Arts, ser. 3, vol. v., 1873, p. 99 (note) ; see also Explora-
tions of Casco Bay by the U.S. Fish Commission in 1873, Proc. Amer. Assoc. Adv. Sci.,
22nd meeting, 1874, pp. 388, 389.

PhascoUon tubicola, Seleuka and de Man, Die Sipunculiden, &c., pp. 24, 25, Taf. vi. tigs. S0-8C.

Body extended. Proboscis longer than the body. The whole body is covered with
papillse, which are small on the anterior portion of the proboscis and on the posterior
half of the body, but are larger in other regions. On the posterior third of the body,
with the exception of a short strip at the very end, there is a zone of irregularly-
scattered, triangular, yellowish-red prickles, with their points directed forwards. The
proboscis bears a few brownish, pointed, unbent hooks which measure 0-06 mm. in length.
There is a circle of from ten to twenty tentacles round about the mouth. Two retracto-
muscles, a thin ventral one and a thicker stronger dorsal one, are inserted with broad
roots near the hind end of the body, and are not united till they have run well forwards.

(ZOOL. CHALL. E.KP.— PART XX.XVI.— 188.5.) Nh 3

18 THE VOYAGE OF H.M.S. CHALLENGER.

The intestine is in loops, and the intestinal spiral exhibits only two coils. The single
short segmental organ opens far behind the anus.

According to Verrill's report, this abundant species is only found in deep water.

Habitat.— Station 49, May 20, 1873; lat. 43° 3' N., long. 63° 39' W. ; depth, 85
fathoms ; bottom temperature, 35° ; gravel, stones ; dredged.

17. PhascoUon botulus, n. sp. (PI. IV. fig. 20).

On the posterior third of the body there are scattered rounded-off attaching papillae
(Haftpapilleu), measuring 0-3 mm. in their greatest breadth and about 0'12 to 0-18 mm.
in height. Two retractor muscles, one very powerful and another weak. Found in
Dentalium shells.

It is impossible for me to give any complete description of this species, since only one
imperfectly preserved specimen, 30 mm. long, was available for examination. This
animal lay within the shell of a Dentalium, wholly embedded in mud. The intestine was
somewhat destroyed by maceration.

One of the above mentioned papillae, found on the posterior third of the body, is
represented in fig. 20. They are distinctly visible to the unaided eye, especially since
their brown pigment stands in marked contrast to the thin colourless skin of the body.

No hooks were to be found. The proboscis was almost completely retracted, in the living
animal it was probably longer than the body, measured from the hind end to the anus.

The tentacles are small and few in number. No exact enumeration was possible.

The root of the more powerful retractor of the proboscis Avas divided into five ; both
retractors originated just in front of the hind end of the body.

The intestine exhibits a threefold, ascending and descending, loop, and the spiral
consists of only two or three coils. The single segmental organ is half the length of the
body, and at its very end is bound by mesentery to the body-wall.

Habitat.— StsLtion 195, October 3, 1874 ; lat. 4° 21' S., long. 129° 7' E. ; depth, 1425
fathoms ; bottom temperature, 38° ; blue mud ; trawled.

18. PhascoUon stromhi, (Montagu) (PI. IV. fig. 21).

Sipuneulus sfrouihus, Montagu, Trans. Linn. Soc. Lond., vol. vii. pp. 74-76, 1804.

Sipunciihis hernhardus, Forbes, A History of British Starfishes, London, 1841, pp. 251-253

(woodcut).
SipunculiiH conchanim, Danielssen, Nj't Magaz. f. Naturvidensk. Christiania, 1861, pp. 57, 58.
Phascolosoma stromhi, Kef'erstein, Beitrage zur Anatomie und System. Kenntniss dor Sipunculiden,

Zeitschr. f. wiss. Zool., 1868, Bd. xv. pp. 430-432, Taf. xxxi. fig. 10, Taf. xxxiii. figs. 34-36.
PhascolosoiiKi stromhi, Selenka and de Man, Die Sipunculiden, &c. (loc. cif.), pp. 50-53.

From among the many descriptions of this species, those above given will lie sufficient
(see the Bibliography in Die Sipunculiden, Selenka, de Man, and Bidow, pp. 50, 53).

REPORT ON THE GEPHYREA. 19

The body is from four to seven times as long as it is broad. Tlie pi-oboscis is as long
as the body or still longer. The skin is tliin and covered with small scattered papillse.
Behind the middle of the body there is a broad girdle of flat attaching papillae, measuring
0"24 mm., and arranged sparingly after a cjuincuncial pattern. In front on the proboscis
there are several rows of simple hooks, whose bases measure about 0'05 mm. The
ventral retractor of the proboscis is united with the dorsal to form one muscle. The
intestinal spiral is short, with only two to four coils. There is on the rectum a small
diverticulum. The contractile tube is without ceeca. The single segmental organ in
fastened to the body-wall by numerous bauds.

Habitat. — H.M.S. "Porcupine," Killibegs Harbour, Ireland, June 24, 18G9.

Genus 8. Aspidosii^hon, Grube.

At the anus and at the posterior end of the body there is a distinct sliield. The
proboscis is very long, and much thinner than the l>ody. It is exccntric, and originates
ventrally from the anal shield. There are almost always hooks present, and these usually
exhibit two forms. The longitudinal musculature may be either continuous or separated
into bands. The tentacles, which are small and finger-shajjed, are few in nuiubei-.
Found in all seas.

19. Aspidosiphon speculatoy, n. sp. (PI. IV. figs. 24-27).

The anal shield is rough and granulated ; the posterior shielil is grooved in a radiate
fashion (with about thirty peripheral grooves). The longitudinal musculature of the
body-wall is divided up into bands.

In the three specimens preserved, the colour of the general body surface was yellowish-
brown, that of the anal and caudal shield dark In-own. The body of the largest imimal
measured 14 mm. in length. The proboscis was of equal length, but one may certainly
suppose that it could be very much elongated, as is the case in all the other species of
Aspidomplion.

In the anterior third of the body there are about twenty-two bundles of longitu-
dinal muscles, anastomosing in a complex manner. Through the other two-thirds of the
body these run in the form of fine distinct bands. The two strong ventral retractors of
the proboscis originate a short way in front of the caudal shield and run together about
half way up the body.

In Aspidosiphon speculator, as in all .species of Aspidosiphon, the tentacles arc few
and short.

The skin glands are supported by countless small plates of chitin, which fonn a i-ino:

20 THE V^OYAGE OF H.M.S. CHALLENGEE.

round the opoiiino- of each gknd. These structures do not, however, form papillte, Ijut at
most appear as flat tubercles when the body-wall is very powerfully contracted.

The whole proboscis is thickly studded with hooks of two forms. On the anterior
half the hooks are flattened, with a strongly curved double point; they measure
0-032 mm. in height, and are arranged in distinct rings. On the posterior half of the
proboscis the hooks are scattered and in the form of three-sided pyramids, with but
sliohtly l)ent points. Over the whole proboscis are seen the openings of the ducts
(0-017 mm. in length) of the cutaneous glands. On the anterior half of the proboscis
these occur in rows between the rings of hooks, about one duct for every three to five
hooks ; on the posterior half of the proboscis they occur much more sparingly, and are
scattered.

The anal and caudal shields are formed from numerous small polygonal or rounded
chitinous plates, which are somewhat larger and thicker round the margins of the shields.

The intestine forms a spiral, and a small diverticulum is present. There are two very
larse seemental organs, which are for half their length attached by means of mesenteries.

St. Vincent (Cape Verde Islands) ; shallow water.

20. Aspidosiphon triincatus, Keferstein.

AspidosipJwn trunmfus, Keferstein, LTntersuclumg iiber eiuige amerikanischc Sipunculiden,

Zeitschr. f. wiss. Zool.,^1866, xvii. p. 50, Taf. vi. figs. 15-18.
Asp!dosipJw7i tnmcafiis, Selenka and Bulow, Die Sipuncnliden, &c. {loc. cit.), pp. 118, 119,

Taf. xiii. figs. 193-195.

The body is brown, the two grooved shields are of a darker colour. The grooves of
the anal shield run from the ventral side to the margin, those of the caudal shield run in
radiate fashion. There are numerous rings of very small bent hooks. The longitudinal
musculature is divided into strands. The retractor of the proboscis has two roots which
originate on the posterior shield. At the point where the intestinal spiral passes into the
rectum there is a diverticulum in connection with the latter. Both segmental organs are
for the most part attached by mesentery to the body-wall.

Of this species a large number of specimens from the Philippines have been preserved,
and I find after examination that they do not in any way difi"er from those forms which
Agassiz found ofi' Panama, and ]\Iobius ofi" Mauritius. The range of distribution must
therefore be very wide. It might indeed be possible on close comparison to establish
between our forms and those investigated by Keferstein a difference great enough to be
considered a specific distinction, but with the form from Mauritius the Philippine species
is certainly identical.

The animals were on an average 17 mm. long, not including the proboscis.

Habitat.— ^t&tion 201, October 26, 1874 ; lat. 7° 3' N., long. 121° 48' E. ; depth, 82
fathoms ; stones and gravel ; trawled.

REPORT ON THE GEPHYREA. 21

Genus 9. Phymosoma, Quatrefages (Selcnka and dc Mau).

Longitudinal musculature divided into bands. There are numerous tentacles arranged
in a single row, not however around the mouth, but above it dorsally in three-fourths of
a circle. The body is covered with papillfe. Hooks arc almost always present. The
intestine is coiled in a spiral fashion. The eggs are elliptical and flattened. The
proboscis has four retractor muscles. There are two eye spots. The members of this
genus arc inostly of considerable size, and the majority are tropical forms.

21. Phymosoma japonicum, Grube.

Phymosoma japonimm, Grube, 51th Jahresbericht der Schlesischen Geselleschaft fiir vaterlan-

(liscbe Cultur, Breslau, 1877, p. 73.
Plnjmosomajcqmnimm, Seleiika and de Man, Die Sipunculidun, &c. (loc. nt.), pp. 76-78, Taf. ii.

figs. 18, 19, Taf. X. figs. 145, 146.

The body is compressed. The proboscis is as long as the l)ody. Even with th(,'
naked eye one can clearly recognise the reddish -brown papilla? on the greyish-brown
body. They are largest and most abundant at the base of the proboscis and at the hinder
end of the body. On the older specimens there may be thirty rings of hooks, and on
the young forms as many as a hundred. These hooks are flattened, measuring 0-07 mm.
in height and the same in breadth ; they have a sharply lient point with a side tooth.
There are not more than twenty-eight tentacles. There may be as many as thirty
longitudinal muscle-bands, which repeatedly anastomose. The intestine exhibits ten to
twelve double coils. The two segmental organs are fixed by mesenteries throughout
half their length.

Habitat. — Port Jackson, shallow water. There were only two tolerably large
specimens.

22. Phymosoma scolo2ys, Selenka and de Man.

Phymosoma scolops, Selenka and de Man, Die Sipuneuliden, &c. {he. cit.), pp. 41, 42, Taf. ii.
fig. 17, Taf. X. figs. 138-144.

A small species with slender body, and proboscis equal to the body in length. The
skin is thin. The proboscis frequently exhibits brown cross stripes on the dorsal surface.
The whole body is studded with small papilliB. The proboscis has about sixteen rings
of hooks, which are bent and measure 0-07 mm. in height, and 0-074 mm. at the base.
On the concave side of the bent point there is a lateral tooth. The tentacles number
twelve or more. There are about twenty longitudinal muscles which rarely anastomose,
but unite just in front of the anus to form a continuous sheath. The four retractors of
the proboscis originate about the middle of the body. The broader ventral retractors

22 THE VOYAGE OF H.M.S. CHALLENGER.

consist of five or six longitudinal muscles, the narrower dorsal of one or two, originating
a short distance in front of the former. The contractile tube is simple. On the intestinal
spiral there are only from twelve to fourteen double coils. The posterior fourth part of
both segmental organs is free.

Habitat. — This species has a somewhat wide range of distribution. Specimens have
been obtained from the Philippines, from Singapore, and from the Eed Sea ; and Peters
found a varietj" off Mozambique.

The single small specimen of the Challenger Expedition was labelled Station 208,
January 7, 1875; lat. 11° 37' N., long. 123° 31' E. ; depth, 18 fathoms; blue mud;
trawled.

In the manuscript left b)^ the late von Willemoes-Suhm I find some sketches and
notes of a Sipunculid, which he considered as representative of a new genus. It is,
however, a true Phymosoma, and seems indeed to be closely related to Phymosoma
varians. But since the single specimen is only imperfectly preserved, so that a
satisfactory diagnosis is now impossible, and since, further, the form exhibits no
characters of special interest, I content myself with this reference.

Genus 10. Sipunculus, Linne.

The longitudinal musculature is divided into seventeen to forty-one bands. The
proboscis has four retractors. The body is destitute of papillae. The tentacles always
surround the mouth, and either form a lobed membrane or are finger-shaped. There are
no hooks, except in Siptonculus australis. Most of the species are large. They are
found in all seas.

23. Sipunculus nudus, Linne.

This species, named by Linne,' is thoroughly described in Die Sipunculiden {loc. cit.),
pp. 92-95.

Habitat. — It has been found in the Mediterranean, on the west coast of France, in the
North Sea, off the West Indies, Florida, and the Philippines. The two specimens
preserved came from the Spanish coast and from the North Sea, and are labelled as
follows : —

(a) H.M.S. " Porcupine," No. 30, August 2, 1870 ; lat. 36° 15' N., long. 6° 52' W. ;

depth, 386 fathoms.
{b) H.M.S. "Porcupine," No. 22, 1869 ; lat. 56° 8' N., long. 13° 34' W. ; depth,
1263 fathoms.

'■ Sy.stema Naturne, Editio duodeciraa I. HolmicT, 176G, p. 1078.

REPORT ON THE GEPHYREA. 23

C. Appendix.

Among the worms entrusted to me for investigation there was a Chcetoderma from
the Malayan Archipelago. In spite of the investigations of Lov^n, Keferstein, Mol)ius,
Graff, and Arnauer Hansen, the systematic position of this animal remains a very debate-
able question. Nor am I able to contribute anything to the elucidation of the problem,
for the single specimen at my disposal was too soft and too easily broken to admit of the
investigation of its internal structure. Nor did the examination of a series of cross-
sections yield me the desired information. This only I am able to affirm, that the
specimen of the Challenger Expedition does not structurally difi'er in any essential point
from the Clioetoderma nitidiihon, Loven, from the North Sea. . There were, however,
noticeable differences in the form of the calcareous spicules, and on these I have been
compelled to base the diagnosis of the species.

Genus 11. Chcetoderma, Loven.

Worm-like hermaphrodite animals without segmentation. A cerebral ganglion and
paired lateral nerve-cords. The mouth bears teeth, and the whole body is studded with
calcareous spicules.

24. ChcBtoderma militare, n. sp. (PL IV. figs. 28-32).

The calcareous spicules of the proboscis are in the neighliourhood of the mouth flat
and elliptical, further back they ar'e larger and have the form of shovel-like or tongue-
like plates, and finally, they gradually become smaller again and take the form of keeled
spear-like points. The body proper bears only a very few thinly scattered rounded
calcareous plates, but at the posterior end there are again large plates, which towards the
anus become long stout prickles with a cross-section between circular and elliptical.
Round about the anus are numerous small prickle-like or awl-shaped calcareous
needles.

Hahitat.—^t'Aiion 210, January 25, 1875; lat. 9° 26' N., long. 123" 45' E. ; depth,
375 fathoms ; bottom temperature 54°'l, surface temperature 80°"2 ; blue mud.

I regret that it is impossible for me to give a more accurate diagnosis of this
species. The only species of Chcetoderma as yet known, namt'ly the Chcetoderma
nitidulum, Loven, was found in the North Sea, and it would have been desirable to
submit to a close comparison forms found in such difl'erent localities.

But since the nature of the calcareous spicules affords a ready distinctive character,
I do not hesitate to establish the single example of the Challenger Expedition as a new

24 THE VOYAGE OE H.M.S. CHALLENGER.

species. In ChcBtoderma nitidulum, Loveu, the calcareous needles, for instance, on the
hind end of the body are, according to Greeff's rejDort (Anatomie des ChiBtoderma
nitidulum, Lovdn, Zeitschr. f. wiss. Zool., Bd. xxvi. Taf. xiii. figs. 24-26), also flattened,
but they are not elliptical in cross-section, like those of Chcetoderma militare. And
again, the spicules on the body of the latter are much less numerous, and we cannot doubt
that the examination of fresh or well-preserved specimens of the tropical form would
reveal other difi"erenccs, which, with the material before me, I am unable to detect.

GEOGRAPHICAL DISTRIBUTION.

The following table exhibits the geographical distribution and the occurrence of the
species described. I have also noted the localities where those species already known
have been previously found.

Species observed in the Challen

ger and '

Porcupine " E.\peditions.

Species previously observed.

"Porcu-

Depth

Character

Name.

Station.

pine"
Voyage.

Locality.

in
Fathoms.

of the
Bottom.

Depth.

Locality.

Stenxaspis princeps, n. sp.

167

lat. 37° 34' S.
long. 179° 22' E.

700

Blue
mud.

Echinrus unicinclics, v. Drasclie.

Japan.

Thalassemafaex, u. sp.

lat. 60° 34' N.
long. 4° 40' E.

560

Thalassema iaronii, Greetl'.

Bahia.

7-20

...

BowMia suhmii, n. sp.

Nova Scotia,
lat. 41° 15' N.
long. 65° 45' W.

1340

Blue
mud.

...

Phascolosoma vtilgarc, Blainville.

lat. 36° 15' N.
long. 6° 32' W.

3S6

...

Near low
water
mark.

West coast of Europe,
Mediterranean, Ked
Sea.

Phascolosoma vuUjare, var. asluta,

lat. 59° 41' N.

458

nov.

long. 7° 34' W.

Phascolosoma pudician, n. sp.

Kergueleu.

10-120

...

Phascolosoma capcnsc, Tcust;her.

Sea Point, near
Cape Town.

Shallow
water.

Cape.

PhascolosonM prioJci, Sluiter.

214

lat. 4° 33' N.
long. 127° 6' E.

500

Blue
mud.

Batavia.

Phascolosoma catlixirina:.

32-3

lat. 35° 39' S.

1900

Desterro.

Fritz Miiller.

long. 50° 47' W.

Phascolosoma flayr if crum, n. sp.

241
45

lat. 35° 41' N.
long. 137° 42' E.
lat. 37° 25' N.
long. 71° 43' W.

2300
1700

...

Dcndrostomn. hlandiim, Sclenka

Yokohama.

5-25

Japan.

and de Man.

Phascolioii lutouic, n. sp.

lat. 62° 26' S.
long. 95° 44' E.
lat. 53° 55' S.
long. 108° 35' E.

1975
1950

Diatom
ooze.

...

Phascolion tuhicola, Verrill.

lat. 4° 21' S.
long. 129° 7' E.

Gravel,
stones.

Frequent-
ly in deep
water.

New England.

Phascolion hotuliis, n. sp.

195

lat. 4° 21' S.
long. 129° 7' E.

1425

Blue
mud.

...

Phascolion stromhi (Montagu).

Kiliibegs Har-
bour, Ireland.

...

North Atlantic.

Plmscolion squamatum, Koreu

358-725

100-200

North Sea, Lofoten, &c.

and Daniclssen.

10
36

Aspidosiplwii speculator, n. sp.

St. Vincent

(Cape Verdes).
lat. 7^3'N.

Shallow
water.

Aspidosiphon trimcatus, Kefer-

201

Stones,

Panama, JIauritius.

stein.

long. 121° 48' E.

gravel.

Phymosoma japonicwm, Grube.

Port Jackson.

Shallow
water.

Japan.

Phymosoma seolops, Selenka and

208

lat. 11° 37' N.

Blue

...

Philippines, Singapore,
Jlozambi(iue, Ked Sea.

de Man.

long. 123° 32' E.

mud.

Sipuncul,us mulus, Linne.

lat. 36° 18' N.
long. 6° 52' W.

386

Mediterranean, West
coast of Europe, West

lat. 56° 8' N.
long. 13° 34' W.

1263

Indies, Philippines.

Chodocicrma militarc, n. sp.

210

lat. 9° 26' N.
long. 123° 45' E.

375

Blue
mud.

(ZOOL. CHALL. EXP. — PART XXXVI. — 1885.)

2sn4

PLATE T.

Fig. 1. Sternas2ns princeps, u. sp.
Three times the natural size ; viewed from the ventral aspect.

Fig. 2. Echiurus unicinctus, von Drasche ; f .

A. Anal vesicles (with ciliated funnels).
a Anal opening.

B. Set£e.

h. The posterior circle of setse.

/3. Fixing muscles of the intestine.

D. Intestinal canal.

a. Diverticulum of the intestine.

g. Blood-vessel accompanying intestine.

K Cloaca.

L. Body-wall.

n. Ventral nerve-cord.

E. Proboscis.

Rm. Circular muscles of the body-wall.

S. Pharynx.

2. vSegmental organs.

sp. Spiral tubes of the segmental organs.

Fig. 3. BoneUia suhmii, n. sp. ; natural size.

The figure is copied from tlie original drawing of Dr. v. WiUemoes-Suhm. Both the
hind end of the body and the proboscis were torn away.

0. Mouth opening. | v. Opening of uterus.

ie Voyage of H.M.S „Challenger.

Gephyrea PI. I

Selenka del.

1.STERNASPIS PRINCEPS n.sp.
Z. ECHIURUS UNICINCTUS v.Drasche 3. BON ELLIA SU HMIl n.sp.

Lith. *nst. y.C. Kiret. Leipziq

PLATE 11.

(ZOOL. CHALL. EXP.— PART XXXVI.— 1885.)— Nn.

PLATE II.

Figs. 4-G. Bonellia suhmii, n, sp.
Fig. 4. The internal structure of the very imperfect specimen represented in fig. 3;
natiu'al size.

i, i. Intestine.
n, n. Nerve-cord.
0. Mouth.

22. The two anal vesicles.

U. Uterus.

Y. Tom loop of the intestine.

Fig,

The uterus, with low power.

T. Ciliated funnel. | m. Efferent aperture.

Fig. 6. The anterior half of an anal vesicle, with medium power.

Figs. 7-10. Male of Bonellia viridis, Eol., from Trieste.

Fig. 7. Adult male 1^ mm. long, with high power. The two hooks had fallen off.
nervous system could not be demonstrated.

Eody-cavity.

The

h. Anterior blind end of the intestine, attached to
the parenchymatous tissue by means of
contractile muscle-fibres.

V. Posterior blind end of the intestine, kept in
situ by means of isolated muscular fibres.

c. Green wandering cells, containing chlorophyll.

d. Connective substance.

e. Ciliated epithelium.
/. Vesicular cells.

rj. Generative opening, and near it some expelled

spermatozoa.
i. Intestine.

Musculature.

Contractile fibres.

Nuclei of the peritoneal epithelium.

Spermatozoa.
s. The right anal vesicle (Analkieme) — seg-
mental organ.
s'. The left anal vesicle ( Analkieme) — segmental

organ.
vcl. Vas deferens.

y, y. External apertures of the segmental organs.
z. Contents of the intestine.

Fig. 8. Cross section in the region A of fig. 7, drawn with the aid of the camera lucida

from a chrom-osmic acid preparation.

n. The inferior swelling of the oesophageal ring (the first pair of ventral ganglia).
The other letters are as in fig. 7.

Fig. 9. Cross section in the region B of fig. 7. Letters as above.

Fig. 10. One of the so-called anal vesicles (segmental organs), with very low power. The
right is always somewhat smaller, and lies somewhat further back than the
left. Each of these segmental organs opens separately to the exterior,
ventrally and laterally. By the contractions of the body- wall the blood
of the body-cavity and with it the free funnels of the segmental organs
are driven backwards and forwards. The rim of the funnel is formed of
from five to seven ciliated cells. The lumen of the segmental duct is
ciliated, but only interruptedly, not continuously.

V. Wall.

u. Lumen with lash-like cilia.

X. Funnel opening.
z. Exterior opening.

The Voyage of H M.S.„Challenger"

■'.■i Pl.ll

^^'^^^^^^i;^!^!^^^^

Selenka del

4-6.B0NELLIA SUHMII,n.sp.
7-10. BONELLIA VIRIDIS Rol.mas.

Lith. Anst . y. C. Kirsl, UipiiJ.

PLATE III.

Figs. 11, 12. Echiurus unicinctus, von Drasche.

Fif. 1 1. The large terminal funnels from the anal vesicles ; x 900. The pointed flagellate
cells of the funnel margin are figured from a fresh specimen of Echiurus
pallasii.

a. The flagellate cells forming the rim of the

funnel.
p. Nuclei of the peritoneum.
i. The internal wall of the funnel.

k. Communication between the canal of the funnel
and the lumen of the anal vesicle.

m. Branched contractile cells occupying the inter-
space between the inner and outer walls of
the funnel.

Fisr. 12. A smaller lateral funnel. Letters as in fig. 11.

Fig. 13. Thalassema faex, n. sp.
Fig. 13. One of the two anal vesicles ; magnified 8 times.

r. Opening into the cloaca.

Figs. 14-16. Phascolosoma pudicum, n. sp.
Fig. 14. Hooks of the proboscis arranged in a ring ; x 140.
Figs. 15, 16. Papillae from the surface of the body ; x 350.

Fig. 17. Phascolosoma flagriferum, n. sp.

Fig. 17. The animal drawn natural size.
a. Anus.

The Voyage of H.M.3„Challenger"

Gephyrea Pll

14.

11,

^%C

16.

17.

Selenka del.

Lith.Arsl.v-C. Kirst, Leifiio.

11-12. ECHIURUS UNIClNCTUS,v.Drasche. 13.THALA3SEMA FAEX,n.sp.
14-16. PHASCOLOSOMA PUDICUM,n.sp. 17. PHASCOLOSOMA FLAGRI FERU M , n. sp.

PLATE IV.

(ZOOL. CHALL. ESP.— PAET XXXVI.— 1885.)— Nn.

PLATE IV.

Figs. 18, 19. Fhascolion squamatum, Koren and Danielssen.
Ficf. 18. The animal magnified 5 times.
Fig. 19. Scales from the surface of the body, seen with low power.

a. A papilla from the proboscis, under liigli power.

Fig. 20. Phascolion hotulus, u. sp.
Fig. 20. Hooked papilla ; magnified 160 times.

Fig. 21. Phascolion strombi (Montagu).
Fig. 21. Specimen from Killibegs Harbour, Ireland ; magnified 4 times.

Figs. 22, 23. Phascolion Intense, n. sp.

Fig. 22. The animal magnified thiice. On the proboscis the cutaneous glands are visible.

Fig. 23. Two adjacent glands with papillae round their openings, from the hind end of
the body ; magnified 200 times.

Figs. 24-27. Aspidosij^hon speculator, n. sp.
Fig. 24. The internal structure ; magnified 5 times.

A. The rough anal shield.
a. Anus.

D. Intestinal spiral.

H. End of proboscis (not stretched out to its
fuU length).

n. Ventral nerve-cord.

E. Proboscis.

Em. Ketractor of the proboscis.

25'. Segmental organs.

S. The caudal shield with its radiating grooves.

Fig. 25. Hooks on the anterior portion of the proboscis ; —^

Fig. 26. Hooks from the posterior portion of the proboscis ; '—.

Fig. 266. Bodies round the opening of the proboscis ; ^.

Fig. 27. Cutaneous glands, with supporting chitinous plates, viewed from above ; ~^.

Figs. 28-32. Chcetoderma militare, n. sp.

Fig. 28. Calcareous spicule, viewed from above and in cross section ; ^^.

Fig. 29. Calcareous spicules from the median portion of the proboscis, viewed from
above and in cross section ; —-.

Fig. 30. Prickle from the posterior portion of the proboscis and from the body ;
magnified 160 times.

Fig. 31. Prickle of the posterior portion of the body, from the side and in cross section.
Fig. 32. The whole animal in its natural size.

;■.

Proboscidal portion. | s. Caudal portion.

The Voyage of H,M.S,„Challenger"

Gephyrea Pi. IV.

19.

W .

22.

23.

25.

'S^^

2G'

31.

28.

29.

/ :

v^^

.30.

32.

*4-

Seienna del.

18-19 PHASCOLION SQ,UAMATUM, KOREN^DAN. 20. PH ASCOLION BOTULUS.nsp

21. PHASCOLION STROMBI.MONT. 22-23. PHASCOLION LUTENSE,nsp

24-27. ASPIDOSIPHON SPECULATOR ,n.sp. 28-32. CHAETODERMA MlLITARE,n sp.

Lith Anst v.C.Ki''st, leipzij.

THE

VOYAGE OF H.M.S. CHALLENGEE.

ZOOLOGY.

REPORT on the Schizopoda collected by H.M.S. Challenger during the Years
1873-76. By Professor G. 0. Sars of the University of Christiania.

INTRODUCTION.

Of the very extensive collections of Crustacea made during the Challenger Expedition,
the two interesting groups, the Schizopoda and the Cumacea, have been placed in
my hands, by Mi\ John Murray, for examination and description.

In the present Report only the first of these groups, the Schizopoda, is treated of.
The Cumacea will subsequently be described and figured in a separate Report, which will
be issued as soon as possible, and to which will be appended a short Report on the
Challenger Phyllocarida.

The collection of Schizopoda procured during the long voj^age of H.M.S. Challenger
has turned out extremely rich and of very special interest, containing, as it does, several
most remarkable new types, the examination of which has led to a much fuller compre-
hension of the morjihology of the Schizopoda and their relation to other Crustacea than
we previously possessed. The various collections having been made in widely distant
tracts of the ocean, an important contribution to the geographical distribution of species
has likewise been acquired.

Very special regard had already Ijcen paid to this interesting group of Crustacea by
the late Dr. R. v. Willemoes-Suhm, whose untimely death, during the Expedition, was
so deeply deplored by his friends and the scientific world.

In a very interesting treatise on the Atlantic Crustacea from the Challenger
Expedition, that appeared in the Transactions of the Linnean Society of London,'

' Trans. Linn. Soc. Land. (Zool.), ser. 2, vol. i. p. 2:$, 1875.
(ZOOL. CHAr.L. EXP. — PART XXXVII.— 188,5.) Oo 1

'2 THE VOYAGE OF H.M.S. CHALLENGER.

this distinguished zoologist has characterised and figured, together with A^arious other
Crustacea, several striking forms of Schizopoda, that have proved to be of a truly remark-
able interest, and which, in the sequel, will be more fully treated of, with due reference
to the treatise of that lamented author.

Moreover, I have had the opportunity of referring to drawings and notes made by
the late v. Willemoes-Suhni during the Expedition, as also to a few jmrtly coloured
sketches of Schizopoda, executed by Sir Joseph Hooker on the Antarctic Expedition in
1839-40, under the command of Sir James Clark Ross, all of which have kindly been
placed in my hands by Mr. John Murray.

In a preliminary paper, published in the Transactions of the Christiania Scientific
Society for 1883,' I have briefly characterised the new genera and species of Schizopoda
from tlie Challenger Expedition, which are more fully described in the following Report.

PiuNciPAL Works on Schizopoda.

Milxe-Edwards, H., Histoire Naturellu des Crustac(5s, t. ii., Paris, 1837.

Bell, T., History of British Stalk-eyed Crustacea, Appendix, London, 1853.

Dana, J. T)., United States Exploring Expedition — Crustacea, part i., Philadelphia, U.S.A., 1852.

Beneden, p. J. v., Eecherches sur la fauna littoral de Belgique — Crnstaces. Mom. Acad. Sci. B'nixnthx,

t. xxxiii., 1861.
Kroyer, H., Et Eidrag til Kundskaben cm Krebsdyrfamilien Mysidce. Nat. Hid. Tidsh:, Raskke 3, Bd. i.,

1861-63.
Claus, C, L'^eber einige Sihizopodeu.und niedere Malacostraken Messina'.-!. Zelindir. f. icii.-i. Zool., Ld. xiii.

p. 422. 1863.
Ueber die Gattung Cynthia als Geschlechtsform der jMy.^ideengattung Siriella. Zaitschr. f. wiss. Zooh.

Bd. xviii. pp. 271-279, 1868.
JSars, M., Beskrivelse over Lophogaster typicus. Universitets program, Christiania, 1862. (Trans.) Ann. mid

Marj. Nat. Hist., ser. 3, vol. xix. pp. 461, 462, 1864.
Sdilm, R. v. AVillemoes-, On some Atlantic Crustacea from the Challenger Expedition. Truna. Linn. Soc.

Lond. (Zool.), ser. 2, vol. i. pp. 23-58, 1875.
Boas, J. E. V., Stuilien fiber die Vervvandschaftsbeziehungen dor Malacostraken. Morphol. JaJirh., Bd. viii.

pp. 485-579, 1883.
Sars, G. 0., Histoire Xaturelle des Crustaces d'eau douee de xsorvege, 1" Livraison, Les Jlalacostraces, Chris-
tiania, 1867.

Monographe over de ved Norges Kyster forekommende Mysider, Christiania, 1870-79.

Middelliavets Mysider. Archiv /. Matliem. og Naturkuiidslcah, Bd. i. pp. 1-111, 1876.

Preliminary Notices ou the Schizopoda of H.M.S. Challenger Expedition. Forhandl. Vidcnsli. S'-lsk.

Christiania, No. 7, 1883.

' Vide, op. cit.

REPORT ON THE SOHIZOPODA.

Terminology.

Concerning the terminology, I have deemed it advisable in the present Report to
make use of that best known and most generally adopted by the carcinologists of the
present time, though I am well aware that the usual terms have not in all cases a
clearly defined scientific character. The manifold modifications, both in structure and
functions, affecting almost every part of the body in this extensive class of Arthro-
poda, must, in my opinion, make it very difficult, if not quite impossible, to establish
any nomenclature, that at the same time would give fully adequate terms for the several
parts, and also be equally applicable to all forms of the class.

The attempts made with this object in view by certain eminent carcinologists, and
most recently by Mr. C. Spence Bate, do not seem to have been generally accepted by
specialists in this department, notwithstanding the great skill and inventive aptitude
shown in constructing the new terms sugfo-ested.

In a strict sense, I think that one of the claims to attention presented by so decidedly
new a terminology would be its unquestionable applicabilit}^ not only to all forms
of Crustacea, but also, as invariably has been attempted with the older one, to its
embracing the other classes comprised in the vast subkingdom of the Arthropoda
(Pycnogonida, Arachnoida, Myriapoda, Insecta). This, however, would appear to have
been far from the object of the above carcinologists. For not only have they restricted
their investigations to the class of Crustacea, but it w^ould also appear that the several
new terms have been, in every sense, specially devised for some limited group of this
class, generally one of the higher ones (Decapods, Amphipods). It is obvious, therefore,
that many of the terms, constructed according to such a method, will not apply even to
aU the Crustacea, let alone to the other Arthropoda.

Indeed, if any attempt be made to construct a new and more generally applicable
nomenclature, it seems imperatively necessary that the terms should be relatively
indefinite, and, as a rule, not involving the designation of any specific physiological
function, but merely structural characters in a more general sense. Only ■\\4thin limited
groups would, perhaps to a certain extent, more definite designations be applicable, but
even then merely as strict specific terms.

It is obvious that several of the new terms j^roposed by Mr. Spence Bate are
of a strictly specific character, e.ij., pereion, pleon, gnathopoda, pereiopoda, pleo-
poda, and these terms therefore cannot, in my opinion, lay any claim to serve as
generally applicable designations for all the Crustacea, although they are extremely
significant and sufficiently adequate for some of the higher gi-oups. Thus any
carcinologist engaged in studying the very extensive order of Copepoda would, I feel
convinced, hardly adopt the terms " pereion " and " pleon " in the same sense as that
proposed \)j Spence Bate ; for in those animals the middle section of the body {" pereion "

4 THE VOYAGE OF H.M.S. CHALLENGER.

of Spenee Bate), and not the posterior, is the one properly corresponding to the
"pleou," its limbs being, in every case, true pleopoda. ^loreover, the zoologist who
has chosen for his special study the Cladocera or the Ostracoda, would hardly be inclined
to apply the term " pleon " either to the middle or the posterior section, but more likely to
the anterior (cephalon), to which are attached the only true swimming limbs (antennge).

Of the limbs belonging to t he middle section of the body, Mr. Spenee Bate names
tlie two anterior pairs " gnathopoda." This certainly may be quite correct as regards a
numlicr of the higher Crustacea, and more especially the Amphipoda, but by no means
for all the lower forms, and the term should therefore merely be regarded as an epithet
for a peculiar modification of those limbs in a few limited groups, precisely as chelipeds,
fossorial legs, prehensile legs, &c.

Even within the restricted group of the Crustacea treated of in the present Report,
which belong precisely to the same division (Podophthalmia) as that on which Mr. Spenee
Bate will report, we find no less than four difterent cases in point, not one of which
would coincide with the proposed terminology. Thus in all known Mysidaj, and among
the Lophogastridse, at least in the genera Lophogaatcr and Ceratolepia, only the most
anterior pair of these limbs can properly be named "gnathopoda." In the Lophogastrid
genus Gnathophausia, too, this pair differs so slightly from the succeeding limbs that,
in a strict sense, the term "gnathopoda" even here is very inappropriate. Again, in
the Euphausiidaj, not only are all the limbs of this section true legs, but even the last
pair of limbs belonging to the anterior section (cephalon) — the maxillipeds — have
assumed a perfectly pediform structure. On the other hand, in the genus Eucopia we
find, exclusive of the maxillipeds, no less than three of the succeeding pairs of limbs
serving as subsidiary organs for mastication, or, more properly, modified as true
gnathopoda.

Moreover, the terms " pleopoda " and "pereiopoda" would not seem to be strictly
applicable to all Schizopoda. Thus, the limbs of the posterior division (" pleopoda " of
Spenee Bate) in all female Mysidas, without exception, and also in some male forms, are
found to be so rudimentary as not to serve in any sense as swimming organs, this
function being merely restricted to the outer Ijranches (exopods) of the limbs belonging
to the middle section of the body (" pereion " of Spenee Bate). Nor is generally the
structure of the true legs in the Schizopoda such as to make them well adapted for the
function of walking, or to serve as true pereiopoda ; thus, in the Euphausiidse the delicate
structure and very restricted mobility of these limbs make them wholly unfit even to
support the body when at the bottom.

Under such circumstances, I have felt some hesitation in adopting for this group of
Crustacea the terminology proposed by Mr. Spenee Bate, although I fully admit the strict
scientific; character and exactness of the terms as regards the greater part of the Podoph-
thalmia. For reasons more fully set forth above, I have deemed it advisable to follow

ItEPOUT ON THE .SCHIZOPODA. 5

the oarlier method, in jiduptiiig for tlic several sections of the liody, as well as for
the respective limbs, designations more indefinite in cliaraeter, and consequently
applicable on a wider scale.

The terms most usually adopted for the two posterior sections of the body, viz., the
"thorax" and " abdomen," are certainly in this respect preferable to tlie much more
specific designations "pereion" and "pleon" proposed by Mr. Spencc Bate. But as
the sections so termed fur tlie Crustacea do not correspond with thos(_- for Insects and
other Arthropods, I have thought it better to select some other known designations of a
similar indefinite kind. The terms "trunk" and " tail" seem to answer the purpose
sufficiently well, and b(jtli have, too, been adopted by some carcinologists.

Concerning the several limbs, I do not regard it necessary to change the well known
and familiar terms " antennte, mandibles, maxillae," which have, moreover, to a great
extent, been adopted for other Arthropods. I have likewise seen fit to retain for the
pair of limbs immediately succeeding the maxillae, the usual term " maxillipeds," more
especially since these limbs, as shown by Milne-Edwards, are found to belong to the
foremost section of the body, and thus in every case, even should their structure
be peculiarly modified, stand in more or less close relation to the oral parts. For all
the limbs belonging to the succeeding or middle section, the indefinite term " limbs of
the trunk" or "legs" may, in a more general sense, be applied, and only in the case of
peculiar structural differences, the more specific terms "gnathopoda, chelipeds, fossorial
legs, perciopoda, whirling legs, natatory legs, prehensile legs," &c., are to be substituted.
As regards the limbs belonging to the posterior section of the body (tail), for the same
reason, the general designation " caudal limbs " may be adopted, and only in particular
cases the specific terms " pleopoda, setiferous laniella3, caudal stylets, opercular and
branchial lamellae," &c. The hindmost pair of caudal limbs, dift'ering in most cases
essentially from tlie preceding, may perhaps be termed, in accordance with the proposal
of Mr. Spence Bate, "uropoda." Together with the last caudal segment (telson) these
limbs form in the liio;her Crustacea the so-called " caudal fan."

To facilitate comprehension of the terminology made use of in the present Report,
the most essential terms are given below. A more detailed explanation woixld, I think,
be quite superfluous.

Adult animal (female, male).

Young animal. Larva (Nauplius-, Zoea-, Mysis-stage).
Pupa (in Lophogastridee and Mysidae).

A. Anterior division of body (cephalon and trunk). Free segments of trunk.

Carapace. — Rostrum (frontal plate) ; cervical sulcus ; lateral wings of carapace ;
dorsal area; regions ; dorsal spine; supra-orbital, antcnnal, and l)ranchio-
.stegal spines.

V Basal part ; masticatory lobes ; palp ; exognatli.

6 THE VOYAGE OE H.M.S. CHALLENGER.

Epistome. — Anterior lip (labrum).
Posterior lip (mctastoma).

1. Eijes. — Pedicle; cornea; ocular papilla.

2. AntennulcB. — Peduncle ; flagella ; male appendage.

3. AntenncB.—'Ra&dl part; terminal part (peduncle and flagellum) ; scale;

basal spine.

4. Mandibles. — Body of mandible ; masticatory part ; cutting edge ; molar

protuberance ; palp.

5. First pair of maxillce.

6. Second pair of maxillcB.

7. Maxillipeds. — Stem (basal part and palp) ; masticatory lobes ; exopodite ;

epipodite.
8-14. Limbs of the trunk or legs. — Stem (coxal, basal, ischial, meral, carpal,
propodal, terminal joints) ; exopod ; epipod ; gills ; incubatory
lamellae ; male sexual appendages.
Incubatory pouch (marsupium).

B. Posterior division of body or tail. — Caudal segments ; epimera ; praeanal spine.

15-19. Caudal limbs (pleopoda ; setiferous lamellse : male copulatory apjsen-
dages).
20. Uropoda, (last pair of caudal limbs). — Basal |)art : terminal plates ;
auditory apparatus (in Mysidte).
^^ 21. Telson (last caudal segment). — Terminal spines; apical incision.

Luminous globules (" accessory eyes " of earlier authors) in Euphausiidse and
Gnathophausia (?).

C'3 ^:S

MORrHOLOGY OF THE SCllIZOrODA.

All the principal tA^^es of this group being represented in the collection made during
the Challenger Expedition, it may, I think, be apposite to discuss here in what relation the
Schizopoda stand to other Crustacea, and what is the systematic position to be at present
assigned to these forms, as also how the group may properly be subdivided.

As is well known, Milne-Edwards, the great reformer of carcinology, ranked these
Crustacea, of which, however, a few forms only had at that time been recorded, side by
side with the Squillacea in his order Stomatopoda, ranging also therein the genus Leucifer
together with certain sjjurious genera, that since then have been found to be only larval
forms of other known Crustacea. Dana, in his great work on the Crustacea of the
United States Exjiloring Expedition, adopts the views of Milno-Edwards as to the
systematic position of the Schizopoda, ranging them in his order Anomobranchiata, which
perfectly corresponds with the order Stomatopoda of the first named author; and several
other carcinologists have since then done the same. Such a classification must, however,
in my judgment, at present be regarded as decidedly unsatisfactory, the Schizopoda
being undoubtedly much more nearly related to the Eubranchiata or Decapoda of Milne-
Edwards than to the Anomobranchiata (Stomatopoda). It will, I think, be absolutely
necessary to restrict the order Stomatopoda to the Squillacea only, a group of Crustacea
(.liffering in many points very materially from all other Podophthalmia, whereas the genus
Leucifer may find its appropriate place side by side with Sergestes, among the lower Deca-
pods (Penseidea). Thus the Schizopoda are either to lie regarded as forming a distinct order,
or to be ranged in the order of the Decapoda or Eubranchiata of Dana. The last men-
tioned view has also been held of late by several distinguished modern zoologists, and
the striking similarity in their external form often exhibited by these Crustacea to the
lower Macrura (Caridea), has even led certain of these zoologists to regard the Schizopoda
as merely forming a section of that tribe of the Decapoda. In my opinion, however,
it is more appropriate at present to assign to this group the rank of a distinct tribe
or suborder, there being several well-marked characters distinguishing these Crustacea
rather sharply from all other known Decapods.

Of such characteristics peculiar to the group, the following may be set forth : —

1. The presence of strongly developed natatory branches (exopods) on all the limbs
of the trunk or legs is, perhaps, the most striking feature distinguishing this group, and

8 THE VOYAGE OF H.M.S. CHALLENGER.

tliat from wliicli the designation Scbizopoda has been dei-lved. There are, it is true,
some few examples of Macruraus in lilce manner retaining the exopods tliroughout the
adult stao-e, viz., the anomalous families Ephyridse and Pasiphaida3, as also certain of
the Penseidea ; but in none of those forms do these parts exhibit the strong develop-
ment peculiar to the Schizopoda, nor do they seem to have any importance as organs of
locomotion.

2. As to tlie oral parts, may be noticed the large size of the mandiljular palp, which
generally even exceeds in length the body of the mandible itself. The maxillse, too,
also exhibit a rather peculiar appearance, different from what is observed in any true
Macruran. It may, however, be remarked, that the oral parts in the Eupliausiidse differ
in several respects very materially from those in other Schizoj^oda.

3. Of the legs, as a rule, only the foremost pair are developed as true gnathopoda,
whereas all the others generally exhibit a very uniform structure, nt)ne of them Ijeing, as
is the case in other Podoplithalmia, modified to cheliform or prehensile organs. In the
Euphausiidae, too, not only are all the legs as a rule uniform, Ijut even the maxillipeds
are quite pediform in structure. The genus Euco'pia exhibits, it is true, in this respect
a very striking anomaly ; it appears, however, that the very peculiar structure of the
legs in that genus is quite as different from what is typical in the higher Podophthalmia.

4. The nK^de in which the ova are borne in the females differs essentially from what
has been ol)served in any other known form of Podophthalmia. In those Crustacea, as
is well known, the caudal limbs (pleof)oda) serve for affixing the roe, whereas in the
Schizopoda the ova are invariably placed beneath the trunk, generally enclosed within -a
pouch, or marsupium, consisting, as in Amphipods and Isopods, of a certain number of
lameUiform leaflets, issuing from the bases of the legs. True, in the Eupliausiidse,
incubatory lamellae are wanting ; but even here the position of the o^-a Iteneath the
trunk is precisely the same as in other Schizopoda.

5. The development of most Schizopoda exhibits a very striking resemblance to that
of the Isopoda, the young passing within the marsupium of the female through one
or more so-called pupa-stages before being hatched. In the Euphausiidae, however, a
totally different mode of development has been discovered, the young of these animals
being hatched in a very immature condition, and not attaining, till after an exceedingly
complicated free metamorphosis, the form characteristic of the adults.

The Schizopoda occupy, as it were, the most primitive jjosition within the division of
the Podophthalmia, being apparently the least modified forms, in which the original
characters distinguishing the progenitors of the whole division would seem to exhiljit
least change. This view derives, too, undeniable confirmation from the fact that a vast
number of the higher Podophthalmia (Macrura, Caridea) pass during development through
a larval stage — the so-called Mysis-stage — calling to mind in a most striking manner the
Schizojiod tvpe.

REPORT ON THE SCHIZOPODA. 9

The suborder Schizopoda, as far as at present known, may be divided into four natural
sections or families, viz., the Lophogastridse, Eucopiidae, Euphausiidse, and Mysidse.
These families are comparatively well defined, exhibiting on the whole very marked
differences, both in the external appearance and in several of the anatomical details, and
also partly in development.

The most highly organised Schizopoda are undoubtedly the Lophogastridae, whereas
the lowest forms are comprised within the family Mysidae. The Eucopiidae would appear
on the whole — notwithstanding the peculiar structure of the legs — to be those most
nearly related to the Lophogastridae. Somewhat more divergent are the Mysidae, which
form an exceedingly rich and at the same time well-defined group of Schizopoda. The
fourth family, the Euphausiidse, occupies in many respects rather an isolated position
within the suborder ; thus, the many remarkable pecuharities distinguishing these forms
have led Dr. Boas^ to exclude them wholly from the Schizopoda, and to establish for
their reception a perfectly distinct order, which, in the opinion of that author, is the
one most nearly allied to the remarkable and anomalous Crustacean Nebalia. Although
in most points I fuUy entertain the views set forth in the very interesting treatise of
Dr. Boas on the affinity of the higher Crustacea, and also admit the significance of the
divergencies distinguishing the Euphausiidae from both the Mysidae and the Lopho-
gastridae, I am by no means prepared to agree with him in excluding these families
from the Schizopoda. In their whole external form and appearance they are true
Schizopods, whereas in these respects they do not show any resemblance to the genus
Nebalia. This form, too, in my opinion ought to be retained within the order Branchio-
poda, representing there, however, a separate section or suborder (Phyllocarida), which in
some respects exhibits a perplexing affinity to higher types of Crustacea.

1 Studieii iiber die Verwandtscliaftsbeziehungen der Malacostraken, loc. cit.

(ZOOL. CHALU EXP, — PART XXXVU. — 1885.) Oo 2

10 THE VOYAGE OF H.M.S. CHALLEXGER.

DEFINITIONS OF THE FAMILIES.

The four families of Schizopoda above mentioned may be briefly characterised as
follows : —

1. LOPHOGASTRID^.

Carapace rather large, more or less calcareous ; its posterior part but loosely covering
the trunk, all segments of which are well defined dorsaUy. Maxillipeds robust, with the
exopodite imperfectly developed, the epipodite very large and projecting within the
branchial cavity. First pair of legs more or less distinctly modified as gnathopoda,
remaining pairs uniform and ambulatory, with well-marked dactylus. BranchisB (arthro-
brauchise) very complex, arborescent, consisting of three or four principal branches, the
innermost largest and freely projecting beneath the trunk, the remaining branches covered
by the carapace, posterior pair rudimentary or wanting. Marsupium in female composed
of seven pairs of incubatory plates. Caudal limbs well developed in both sexes and
of uniform structure, natatory. Development without any free metamorphosis.

Genera.

1. Lophogaster, M. Sars.

2. Ceratolepis, G. 0. Sars.

3. Gnathophausia, Suhm.

4. Chalaraspis, Suhm {ex parte).

2. EUCOPIID^.

Carapace very large, membranous, the lateral wings produced and projecting over the
base of the tail. Segments of trunk all well defined. Maxillipeds nearly the same as in
the Lophogastridse. Legs dissimilar in structure, the three anterior pairs modified to
serve as gnathopoda, the three succeeding pairs extremely slender, filiform, wdth the
dactylus falciform and very mobile, last pair simj)le, not prehensile. Branchise,
marsupium, and caudal limbs nearly the same as in the Lophogastridse. Development ?

Genus.

Eucopia, Dana.

3. EUPHAUSIID^.

Carapace rather small, not calcareous, firmly connected with the trunk along the dorsal
face, leaving only part of the last segment closed above. Maxillipeds elongate, pedi-
form, with the exopodite well developed, natatory, the epipodite rudimentary or wanting.

REPORT ON THE SCHIZOPODA.

Legs generally uniform in structure, not adapted for walking, geniculate and densely
setose, without any distinct dactylus ; posterior pairs more or less imperfectly developed.
Brancliise (podobrancluje) wholly uncovered, digitiform-arboresccnt, the posterior pairs
rather complex, sending ofi" a branch beneath the trunk. Egg-pouch, when present,
placed beneath posterior part of trunk, single or double, not formed by any incubatory
lamellae. Caudal limbs strongly developed in both sexes, natatory, inner plate provided
with a secondary lobe, and in the male modified on the first two pairs as copulative
organs. Luminous globules of complicated structure generally present on both the
anterior and posterior divisions of the body. Propagation by means of spermatophores.
Development very complex, the free larva passing through the Nauplius and Zoea-stages.

Genera.

1. Eiiphaima, Dana.

2. Thysanopoda, M.-Edw.

3. Bentheuphausia, n. gen.

4. Nyctiphanes, G. 0. Sars.

5. Boreophausia, n. gen.

6. Thijsanoeisa, Brandt.

7. Nematoscelis, G. 0. Sars.

8. Stylochdron, G. 0. Sars.

4. Mysid^.

Carapace generally rather small ; its posterior part only loosely covering the trunk,
the segments of which are distinctly defined, although very narrow and crowded together
in the dorsal part. Maxillipeds strong, with the exopodite well developed, natatoiy,
epipodite lanceolate and projecting within the branchial cavity. First pair of legs
modified as gnathopoda, the remaining legs uniform and generally of rather feeble
structure, the terminal part being in most cases subdivided into short setiferous articula-
tions, the dactylus, as a rule, small or wanting. No true branchiae present. Marsupium
in most of the genera composed of only two or three pairs of incubatory lamellae, issuing
from the bases of the hindmost pair of legs. Caudal limbs in female quite rudimentary,
not adapted for swimming ; in male either natatory or some of them modified to serve as
copulative organs. Inner plate of uropoda generally containing within its base a
peculiarly developed auditory apparatus. Development without any free metamorphosis.

Geiiera.

1. Petalopkthahmis, Suhm.

2. Boreomijsis, G. O. Sars.

3. Amhhjops, G. O. Sars.

4. Fseudo77inia, G. 0. Sars.

5. Erythrops, G. 0. Sars.

6. Parerythfops, G. 0. Sars.

7. Anchialus, Krdyer.

8. Mysidopsis, G. 0. Sars.

9. Leptoinysis, G. 0. Sars.

10. Siriella, Dana.

11. Mysideis, G. 0. Sars.

12. Promysis, Dana.

13. Euchcetomera, G. 0. Sars.

14. Hemimijsis, G. 0. Sars.

15. Mysis, Thompson.

16. Macropsis, G. 0. Sal's.

17. Mysidella, G. 0. Sars.

18. Heteromysis, Smith.

THE VOYAGE OF H.M.S. CHALLENGER.

LIST OF THE SPECIES.

The following is a list of the species
Expedition : —

LOPHOQASTRID^.

1. Lophogaster typicus, M. Sars.

2. Cerafolepis hamata, G. 0. Sars.

3. G-nathophausia ingens (Dohrn).

4. „ gigas, Suhm.

5. „ calcarata, G. 0. Sars.

6. „ willemoesii, G. O. Sars.

7. „ affinis, G. 0. Sars.

8. „ elegans, G. 0. Sars.

9. „ zoea, Suhm.

10. „ longispina, G. O. Sars.

11. „ gracilis, Suhm.

12. Chalaraspis alata, Sulim, M.S.

EUCOPIID^.

13. Eaeopia anstralis, Dana.

Edphausiid^.

14. Euphausia pellueida, Dana.

15. „ similis, G. 0. Sars.

16. „ eplendens, Dana.

17. „ murrayi, G. 0. Sars.

18. „ superba, Dana.

19. „ antarctica, G. 0. Sars.

20. ,, viueronata, G. 0. Sars.

21. „ gracilis, Dana.

22. „ gibba, G. 0. Sars.

23. „ spinifera, G. 0. Sars.

24. „ latifrons, G. 0. Sars.

25. Thysanopoda tricuspidata, M.-Edw.

26. „ obtusifrons, G. O. Sars.

27. „ cristata, G. 0. Sars.

of Schizopoda procured during the Challenger

28. Thysanopoda mieroplithalma, n. sp.

29. Bentheuphausia amblyops, G. 0. Sars, n. gen.

30. Nyctiphanes australis, G. O. Sars.

31. Thysanoessa gregaria, G. 0. Sars.

32. „ macrura, G. 0. Sars.

33. Nematoseelis megalops, G. 0. Sars.

34. „ mierops, G. O. Sars.

35. „ tenella, G. 0. Sars.

36. „ rostrata, G. 0. Sars.

37. Stylocheiron carinatum, G. 0. Sars.

38. „ suhmii, G. 0. Sars.

39. „ longicorne, G. 0. Sars.

40. „ elongatum, G. 0. Sars.

41. „ abbreviatum, G. 0. Sars.

Mysid^.

42. Petal opJithalmus armiger, Suhm.

43. Boreomysis scyphops, G. 0. Sars.

44. „ obtKsata, G. 0. Sars.

45. ,, mierops, G. 0. Sars.

46. Amblyops crozetii, Suhm, M.S.

47. „ amtralis, G. 0. Sars. '

48. Pseudomma sarsii, Suhm, M.S.

49. Anchialus typicus, Kroyer.

50. „ angustus, G. 0. Sars.

51. „ pusilhis, n. sp.

52. Mysidopsis (?) ineisa, G. 0. Sars.

53. Siriella thompsonii, M.-Edw.

54. „ gracilis, Dana.

55. Euchcetomera typica, G. 0. Sars.

56. „ tenuis, G. 0. Sars.

57. Heteromysls berrmulensis, n. sp.

DESCRIPTION OF GENERA AND SPECIES.

Order PODOPHTHALMIA.

Suborder SCHIZOPODA.

Family 1. Lophogastrid^.

This family, formerly represented only by a solitary genus, Lophogaster, has acquired
a very considerable augmentation by the material collected during the Challenger Expedi-
tion, three interesting new genera having been added, one of which (Gnathophaitsia) is
represented by no less than nine different species.

I have placed this family at the head of the suborder, since it would seem to comprise
the most highly organised forms of Schizopoda. This may easily be shown by comparing
the structure and development of the several organs with the corresponding ones in other
Schizopods, and especially by examining the branchial apparatus, the highly differenti-
ated structure of which gives full evidence of the high rank occupied by these forms.
The fact that by far the largest and most powerfully developed species are to be found
in the present family, would seem also to support such a view.

The late Professor M. Sars, my father, had already stated that the genus Lopliogaster,
which constitutes the type of this famil}^, exhibits in several respects a striking affinity to
some of the lower Macrura (Caridea). Exclusive of the strong development of the gills,
may also be noted the structure of the integuments, which are more or less calcified or
indurated, and in some cases even exhibit a distinctly perceptible sculpture, not to be
found in any other Schizopods ; moreover, the comparatively powerful structure of the
legs renders those organs apparently more efficient for the office of true pereiopoda, than
is the case with the other known forms of this suborder. From the Macrura they may,
however, be easUy distinguished, not only by the incubatory pouch of the females, but
also by the uniformly developed biramous legs, none of which exhibit any trace of a
cheliform or even subcheliform structure.

A sjTiopsis of the four genera comprised in this family is given below : —

Carapace

covering only the
anterior division of
the body. Rostrum

short, forming together
•with the supra-
orbital spines a broad
tridentate frontal plate.
Antennal scale

broad, cordifomi, with
the inner edge

setose, .

narrow,
without
set*,

flexuous,
marginal

Lophogaster.

Ceratolepis.

more or less produced, spear-shaped, denticulate, Gnathophausia.
covering whole of tlie anterior division of the body and part of posterior, . Chalaraspis.

14 THE VOYAGE OF H.M.S. CHALLENGER.

Genus 1. Lophogaster, M. Sars, 1856.

Lophofjaster, M. Sars, Forliandl. Skand. Naturf., Mode i Cliristiania, 1856, p. IGO.
Ctenomysis, Norman, Rep. Brit. Assoc, 1861, p. 151.

Generic Characters. — Carapace distinctly sculptured, forming anteriorly a broad
tridentate frontal plate, posterior margin deeply emarginate in the middle, leaving last
segment of trunk wholly exposed above, lateral wings produced, pointed. Caudal
segments with well-defined lamellar epimera, last segment subdivided by a transverse
suture. Eyes globular, partly covered by the frontal plate. Antennular peduncle very
short and thick, inner flagellum small, outer remarkably strong and elongate. Antennal
scale cordiform, outer edge serrate, inner setose. First pair of maxillse without any
palp, second pair with only two masticatory lobes ; palp comparatively small. First pair
of legs (gnathopoda) with terminal joint obtusely rounded and densely hirsute. The
remaining legs rather robust, with strongly developed dactylus. Branchiae tripartite, the
branches regularly bipinnate, and each pinnula exhibiting a double series of small
leaflets. Telson produced, with apex entire, and armed with strong terminal spines.
Outer plate of uropoda not subdivided at extremity, outer edge straight, and terminating
in a small dentiform projection.

Remarks. — In the above diagnosis I have made an attempt to arrange together several
characters, that in my opinion should be regarded as peculiar to the present genus, when
compared along with the three new genera brought to light by the Challenger Expedition.
The genus which, as that first established, may be taken to be the type of the family, is
as yet represented only by a single species, Lophogaster typicus, formerly regarded
exclusively as a northern form, but now having also been met with during the Challenger
Expedition, proved to exhibit a very wide geographical distribution.

1. Lophogaster typicus, M. Sars (PI. 1. figs. 1-7).

Lophogaster typicus, M. Sars, Forhandl. Skand. Naturf., Mode i Cliristiania, 1856, p. 160.
Ctenomysis alata, Norman, Rep. Brit. Assoc., 1861, p. 151.
Lophogaster typicus, M. Sars, Univ. Progr., 1862.

Of this interesting Schizopod, fully described by the late Professor M. Sars, there are
three more or less complete specimens in the Challenger collection, from two Stations, at
no great distance apart, both south of the Cape of Good Hope. One of the specimens is
a full-grown male, the other two (one of which is defective) are females.

I have most carefully compared these specimens with the form occurring on the
Norwegian coast, without, however, having detected any distinctive character warranting
the assignment of specific diiference, and henc6 I am obliged to regard them as
belonging to the typical species, notwithstanding the remarkable fact of their occurrence
in a locality so widely distant from the Norwegian Sea.

REPORT ON THE SCHIZOPODA. 15

To show the correctness of this assumption, and at the same time afford other
zoologists an opportunity of instituting a comparison, I have given on the first Plate
of the present Report figures of the Challenger specimens, and subjoin the following
descriptive notes.

The male specimen (fig. 1) has a length of 25 mm., and is distinguished from
the female (fig. 2) by a somewhat more powerful development of the tail, as also by
the greater length of the outer antennular flagellum.

The broad frontal plate, which is hollowed in the centre (fig. 3), has the median tooth
(rostrum) rather short, not exceeding in length the lateral teeth (supra-orbital spines),
and covers, as in the Norwegian form, not only a great pail of the antennular jieduncles,
but also the bases of the globular eyes, forming here a kind of imperfect orbit.

The antennal scale (fig. 3) exhibits the peculiar cordiform shape characteristic of the
species, but in the present specimen is distinguished by the unusually small numljer of
teeth (only three) on the outer margin.

Having examined a series of Norwegian specimens, I find, however, that the number
of teeth along the outer edge of the antennal scale, as well as the relative length of the
teeth on the frontal plate, is subject to a rather considerable variation. This, too, is
obvious on comparing the male specimen here described with the two other specimens
procured from the Challenger Expedition, which are both females.

One of these females, the most perfect, is represented in fig. 2, viewed from above.
It has a length of 18 mm., and thus is somewhat smaller than the male specimen, a
fact in accordance with that observed in the Norwegian forms, the females of which
are, as a rule, considerably smaller than the adult males.

It wiU be observed, that the median tooth of the frontal plate in this specimen is
rather more produced than the lateral teeth, reaching almost to the end of the antennular
peduncle. Moreover, the number of teeth along the outer edge of the antennal scale
(fig. 4) is greater, as many as five having been counted.

Of the legs, I have figured one belonging to the last pair (fig. 5) in the imperfect
female specimen. On comparing this figure ^\ath the one given by my father of
the same leg in a Norwegian specimen^ the resemblance between the two is very
striking.

The caudal fan (fig. 6) also exhibits in all its details the most perfect agreement
with that of the Norwegian form. The telson, considerably exceeding in length the
uropoda, is scooped out dorsally along the middle, exhibiting two parallel longitudinal
carinse, most prominent in the posterior part. It tapers gradually towards the apex,
and, a little posterior to the middle, is provided on either side with tluree small lateral
denticles. To the truncate extremity of the telson are attached four strong spines, and
a little anterior to them is observed another somewhat smaller spine on either side. In

1 See Univ. Progr., pi. ii. fig. 36.

16 THE VOYAGE OF H.M.S. CHALLENGER.

the middle, between the two larger apical spines, projects moreover a thin and finely-
serrate lamella, to the lower side of which are attached two delicate diverging bristles.
This serrate lamella is not figured distinctly in the work of the late Professor M. Sars,
although it is mentioned in the text. However, on re-examining the Norwegian form
I have found it to be present, and in form and armature of precisely the same appearance
as in the specimen here figured (fig. 7).

Habitat. — The specimens procured by the Challenger Expedition were collected at
the followino- Stations : —

Station 141, December 17, 1873 ; lat. 34° 41' S., long. 18° 36' E.; depth, 98 fathoms;
green sand ; bottom temperature, 49°'5.

Station 142, December 18, 1873; lat. 35° 4' S., long. 18°37'E.; depth, 150 fathoms;
green sand; bottom temperature, 47°'0.

The present species occurs rather abundantly along the southern and western coasts
of Norway at a depth of from 20 to 100 fathoms, and has also been recorded from the
Shetland Isles by the Rev. Dr. Norman ( = Ctenomysis alata of that author).

It may be regarded as a true bottom-form, never having been found at the surface of
the sea, as is the case with some other Schizopods.

Distnhution. — Concerning the geographical distribution of the species, the occurrence
of this form in the southern hemisphere, as shown by the Challenger collection, is remarkable,
and might induce the belief that it ranges from the Norwegian Sea along the whole western
coast of Europe and Africa, or thi-oughout the boreal, lusitauic, tropic, and antiboreal
regions. It may, however, be considered as a highly remarkable fact, that this very
striking form has never been recorded either from the coasts of England and France, or
from the Mediterranean, although each of these tracts has been carefully investigated by
numerous zoologists. We may therefore entertain the assumption that this form in
reality does not occur throughout the intermediate tracts of the ocean, but is met with
independently in both hemispheres in the corresponding region. Should this be the case,
we may infer that the distribution of the species must at an earlier date have been
continuous, but considerable changes afterwards occurring in the physical conditions led
to a separation of the species into two independent stocks. In the sequel we shall meet
with another still more striking example of a similar kind, in treating of the Mysidian
Boreomysis scypliops, a form stated to occur in the Arctic and Subantarctic regions only,
having never yet been found in any intervening tract.

REPORT ON THE SCFIIZOPODA. 17

Genus 2. Ceratolepis, G. 0. Sars, 1883.

Ceratoh'pis, G. O. Sars, Piulimiuary Notices on the Cliullonger Schizopoila.

Generic Characters. — Carapace highly indurated and very large, covering the whole
of the anterior division of the body, posteriorly abruptly truncate, not emarginate,
anteriorly forming a broad tridentate frontal plate, as in Lophoganter. Caudal segments
comparatively short and narrow, with small epimera; the last not subdivided by any
transverse suture. Antennulse similar to those of Lophogaster. Antcnnal scale very
peculiar, forming a narrow flexuous plate of firm consistence, without any trace of
marginal bristles. Logs of comparatively more feeble structure than in Lo2^hogaster,
first pair modified so as to form gnathopoda, last pair (in female) without natatory
branches. Telson bifid, without distinctly articulated spines. Uropoda very small, the
terminal plates uniform, lanceolate and setose on Ijoth margins.

Remarks. — This new genus is obviously rather closely related to Lophogaster, differ-
ing however, in addition to other characters, very distinctly in the form of the carapace,
the very remarkable structure of the antennal scale, the want of distinctly developed
exopods on the last pair of legs, and finally in the structure of the telson and uropoda.
The genus comprises at present but a single species, of which a solitary specimen only
was collected by the Expedition.

2. Ceratolepis hamata, G. 0. Sars (PL I. figs. 8-17).

Cendnlepis hamafa, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 2.

Specific Characters. — Form of body rather short and robust. Carapace slightly
nodulose above, with the dorsal area distinctly marked. Median tooth of the frontal plate
conically produced, and reaching to the end of the antennular peduncle, lateral teeth
much shorter and somewhat deflexed. Epimera of the caudal segments finely serrated on
the posterior margin. Last segment jutting out posteriorly into four rather large projec-
tions, two lateral and two terminal, the latter embracing the base of the telson. Eyes
rather small, almost wholly covered above by the frontal plate. Antennal scale con-
siderably projecting in front of the antennular peduncle, slightly curved outward
and somewhat dilated nt the apex, forming there two acute angles, the one pointing
forward, the other recurved in the shape of a hook ; internal margin angular in the
middle. Telson deeply cleft at the apex, terminal lobes acuminate and diverging.
Length, 12 mm.

Remarks. — The species here treated of being the only one yet established in the genus
Ceratolepis, it is no easy matter to decide with certainty what characters should be
regarded as of specific significance. I have, however, sought in the above diagnosis to
adduce some few distinctive peculiarities, that may perhaps be of weight in this respect.

(ZOOL. CHALL. EXP. — PAET .XXXVII. 1885.) Oo 3

18 THE VOYAGE OF H.M.S. OHALLENGER.

Description. — The specimen examined is a female, and may be assumed to be nearly
full grown, since tLe incubatory lamellae are distinctly perceptible beneath the trunk,
though still rather small, and not as yet forming atiy marsupium. The length, too, of
the animal does not exceed 12 mm., and hence this form would a^jpear to be the smallest
of the known Lophogastridaj.

The general form of the body (see figs. 8 and 9) is comparatively short and thickset,
resembling on the whole that of Lopliogaster, with this difference, however, that the
anterior division, owing to the strong development of the carapace, appears somewhat
larger when compared with the posterior.

Contrary to what is usually found to be the case in Schizopods, the integuments are
remarkably firm and highly indurated, giving to the whole body a peculiar rigidity,
somewhat resembling the higher forms of Macrura.

The carapace is of very considerable size, fully equalling in length the tail, if the telson
be excluded. It completely covers the whole anterior division of the body in such a manner
that none of the segments of the trunk are dorsally exposed. Its surface is rather uneven,
exhibiting, more particularly in the upper part, a peculiar rugged or wrinkled aspect
(see fig. 8). A distinctly impressed line marks off above, as in Lopliogaster, a somewhat
Hnguiform dorsal area, terminating . about the beginning of the posterior fourth of the
carapace. Posteriorly to this area, and laterally, the carapace covers the trunk but
loosely, whereas within the area it forms the immediate wall of the body. Anteriorly, the
carapace projects as a broad, horizontally extending frontal plate, covering the eyes
and a great part of the antennular peduncles, as in Lophogaster. This plate juts out
in the middle as a conical process, reaching to the end of the antennular peduncle, and
more properly answering to the rostrum. The lateral edges of the frontal plate (the
supraorbital spines) form similar processes, though somewhat shorter and more deflexed
(see fig. 8). The inferior margins of the carapace are but very slightly arcuate, and
terminate anteriorly almost in a right angle. The posterior margin, too, is abruptly
truncate, not as usual emarginate in the middle, and the lateral wings of the carapace do
not project at all posteriorly.

The posterior division of the body, or tail, is comparatively short and narrow,
exhibiting dorsally a similar rugged appearance to the carapace, the median part of
every segment being rather convex, whereas at both extremities a distinctly perceptible
transverse impression occurs. The epimera are rather small, of an obtusely triangular
form, and finely serrated at the posterior margin toward the apex (fig. 16). The first
segment has on either side an anteriorly pointing projection, fitting in beneath a
short corresponding lateral keel on the posterior part of the carapace when the
tail is fully extended (see fig. 8). The last segment is not much longer than the
preceding, but rather narrower. It has no trace whatever of the transverse
suture observed in Lophogaster, but exhibits posteriorly on either side a strong

REPOKT ON THE SCHIZOPODA. 19

triangular projection, as also two posteriorly curved mucroniform spines, embracing the
base of the telson.

The eyes (see fig. 10) arc comparatively small, and almost wholly covered above by
the frontal plate, without, however, being lodged, as it were, within orbital hollows,
as in Lophogaster. The cornea occupies a comparatively small part of the eyes, and does
not exhibit any appreciable dilatntion; its pigment is dark, and the visual elements are
normally developed.

The antennular peduncle (fig. 1 1 , a') is short and thick, not, however, to such an
extent as in Lophogaster. The last joint does not exceed the basal in length, while in
Lophogaster it is even larger than the two remaining joints taken together. As in the
latter genus, the basal joint is somewhat applanated, and jirojects exteriorly as a pointed
lappet. Of the flagella, the inner is very small, scarcely more than lialf as long as the
peduncle, and composed of rarely more than ten short articulations. The outer
flagellum, too, would seem to have been much more strongly developed, but its length
cannot be exactly stated, the terminal part having been broken off in the specimen examined.

The basal part of the antennse (see fig. 11) is thick and highly chitinised, forming
on the externa] side a keeled prominence. The terminal part (a^) is of the same
structure as in Lophogaster. On the other hand, the scale (fig. 11, .<<q; fig. 12)
exhibits a totall)' different and very peculiar appearance. It is almost twice as long as
the antennular peduncle, and has the form of a very narrow, strongly chitinised, and
somewhat flexuous plate, without any trace of the usual marginal bristles, but jDrovided
with several strong angular projections. The exterior part of the plate is rather
prominently curved outwards and somewhat dilated at the apex, which projects in two
acute angles, the one pointing straight forward, the other recurved in the shape of a
hook. In the middle, the inner edge of the plate forms a similar recurved projection, and
in front of this may be observed another short angular prominence. As regards both
form and structure, this scale is wholly dissimilar to anything obsei'ved in other known
Podophthalmia, and hence it undoubtedly represents one of the features most characfer-
. istic of the genus.

Concerning the oral parts, they would appear, on the whole, so far as they admit of
being examined in the only specimen obtained, to agree with those in Lophogaster.
Viewed from below (fig. 11), the following parts may be more or less distinctly observed
within the comparatively very broad buccal area ; anteriorly, on the median line appears
the galeate anterior lip {L), and on each side the mandibles {M), with their palps (/>),
which are very elongate and slender ; posterior to the mandibles are the maxilLi?, of
which, however, only the second pair admit of being partly examined, their exognaths
(jni?) being wholly exposed and rather large, elliptic, and fitting into a semicircular
opening, that leads to the branchial cavity ; they are as usual fringed with a row of
strong ciliated bristles. The maxillipeds (mp) marking off posteriorly the buccal ;irea,

20 THE VOYAGE OF H.M.S. CHALLENGER.

exhibit a structure perfectly similar to that in Lophogaster, the exopodite here also being
imperfectly developed, forming only a very small setous lamella {x).

The first pair of legs (fig. 13), as in Lophoyaster, differ perceptibly from the
remaining pairs, being somewhat more robust in structure, and having the terminal
joint not unguiform, but of an oval shape, and densely beset with bristles. Hence this
pair may properly be regarded as true gnathopoda.

The remaining legs (fig. 14) are all true pereiopoda, but have comparatively a more
feeble structure than in Loj^hogaster, with the carpal joint more elongate, whereas the
terminal one, or dactylus, is much shorter.

The last pair of legs (fig. 15) are chiefiy distinguished by the want of natatory
branches or exopods, in the place of which only a diminutive setous tubercle is to be seen.
This, however, may perhaps be a characteristic peculiar to the females.

The caudal limbs (see fig. 8) are normally developed, and do not seem to differ essen-
tially in structure from those in Lophogaster.

The telson (fig. 17) somewhat exceeds in length the two jjreceding segments taken
together, and exhibits a form similar to that in Lophogaster, but differs materially in
the apex not being entire but deeply cleft, or produced into two acuminate and
diverging lappets, somewhat resembling the tail of a swallow. The inner edge of these
terminal lappets is indistinctly serrated. For the rest every trace of spines or bristles is
entirely wanting.

The uropoda (fig. 17) are most unusually small, being scarcely half as long as the
telson, and with both their terminal plates of a uniform appearance, lanceolate, and setose
on both margins.

Habitat. — The solitary specimen described above I found in a .small bottle containing
Euphausiidse, larvae of Macrura, and certain other pelagic animals, all of which, as shown
by the label, were collected at the surface of the sea in the Pacific Ocean, l)etween Api
(New Hebrides) and Cape York (Australia).

This occurrence, certainly, is very remarkable, since none of the other Lophogastridse
are known to lead a pelagic existence. Indeed, judging from the organisation of the
present species, and more especially the very firm and highly indurated integuments, one
would indeed be induced to regard it as still more decidedly a bottom form than
most of the other Schizopods.

Genus 3. Gnathophaiisia, Willemoes-Suhm, 1879.
Gnalhophausia, Sulim, Trans. Linn. Soc. Lond., scr. 2, vol. i.

Generic Characters. — Integuments generally not very firm, }>archment-like. Carapace
rather large, in the greater part of its length only loosely covering the trunk, and
exteriorly provided with raised longitudinal keels. Rostrum more or less elongate and

KEPORT ON THE SCHIZOPODA. 21

slender, spear-shaped, three-edged, (U'liticuhitc IliudcT part of carapace f(jr the most
part drawn out dorsally into a posteriorly pointing spine. Caudal segments narrow, with
small, bilobed epimera ; the last subdivided transversely. Eyes well developed, with a
small papilla issuing from the pedicle anteriorly. Antennular peduncle short and thick,
outer flagellum greatly produced, riband-shaped. Antennal scale of somewhat varying
form in different species. First pair of maxillae provided with a biarticulatc, setous palp,
completely recurved, posteriorly. Second pair exhibiting at the base exteriorly a pigmented
protuberance (luminous organ ?) ; anterior masticatory lolje cleft to the base int(j two
very narrow lappets ; palp rather large. Maxillipeds having exopodite either very small
or entirely wanting. Legs slender, nearly uniform, ambulatory; first pair differing very
slightly from the rest. Branchia3 divided into four bipinnate ramifications, pinnulse
exhibiting irregularly disposed, digitiform lobules. Telson very large, constricted near
the base, lateral edges densely spinulous, apex armed with two strong curved spines con-
nected at the base. Uropoda with the outer plate broader tliau the inner, and having a
short dentiform projection at the end of the outer margin, the terminal lobe being marked
off by a distinct transverse suture.

Remarks. — Of the earlier known Schizopods, Lophogaster certainly comes nearest to
the present interesting genus, first established by the late Dr. v. Willemoes-Suhm,
and I fully agree with that author in including it in the same family with that
genus. On the other hand, it will appear from the diagnosis given above, that the
genus here treated of exhibits several very striking features, distinguishing it rather
clearly from the other Lophogastridfe. Moreover, the' general appearance will be found
to diverge a good deal from that observed in the two preceding genera.

To our knowledge of the present remarkable genus a very important contriljution has
been fui'nished by the Challenger Expedition, no less than nine different species being
represented in the collection. Of these species, only one, Gnathophausia ingens, had
been recorded at an earlier date ; all the remaining species were first discovered during
the course of the Expedition.

With a view of obtaining a clearer survey of the organisation of this interesting type,
I have deemed, it advisable to give a general description of the genus, previously to
characterising the several species comprised therein.

General Description of the Genus. — The form of the body (see figures given in Pis. II.
to VII.) wiU be found to vary somewhat in the different species, mainly owing to the more
or less prominent development of the carapace. In all the species, however, the tail is
very slender, almost cylindrical in form, and its segments provided with rather small
epimera, divided into two more or less produced lappets. The last segment exhibits, as
in Lophogaster, an obliquely transverse suture, thus apparently subdividing it into two
sections, the anterior of which is provided with a pair of imperfectly developed, and, in
some species very peculiarly formed, epimera.

22 THE VOYAGE OF H.M.S. CHALLENGER.

The carapace in all the species is rather large, almost covering the whole anterior
division of the body, not, however, being connate, only to a rather limited extent.
When viewed from above it exhibits anteriorly (see Pis. IL, III., IV., V. fig. 2)
a short linguiform area, sharply marked off behind by a curved line. This dorsal
area projects from the so-called stomachal region, and generally does not even
reach posteriorly the middle of the caraj^ace. Only within this restricted area,
and in front of it, does the carapace constitute the true body- wall ; behind it
covers, though very loosely, the trunk, all the segments of which appear well
developed in their whole circumference, and exhibit a rather uniform aspect (see
PI. VIII. fig. 17). Thus the greater part of the carapace, as in the genus Nehalia, would
appear to form, so to speak, merely a loose mantle arching the back and sides of the
trunk, and within which the body is freely movable ; a character also regarded by the
late Dr. v. Willemoes-Suhm as more particularly ■ distinguishing the present type.
This mantle-like portion of the carapace, likewise found, though generally less pro-
minently developed, in the other Lophogastrida^, as also in Eucopia and in the Mysidse,
exhibits in Gnathoj^ihausia on each side two more or less well-marked longitudinal keels,
dividing this part into five areas, the odd one in the middle, limited by both of the upper
keels, with a lateral area on each side, between the upper and lower keels, finally a much
smaller marginal area, extending between the lower keel and the free edge of the
carapace, the last being strongly inflected toward the ventral face. The lateral areas
occupying most of the sides of the carapace, are bounded anteriorly by an obliquely
descending elevated line, corresponding, in position, with the branchiostegal line of the
higher Podophthalmia, and terminating just above the liuccal area. Immediately below
this line, the carapace forms a more or less marked lateral expansion, jutting out in some
species into a strong, exteriorly pointing projection, which I regard as the branchiostegal
spine.

Viewed from below (see PI. IV. figs. 3 and 4), the free margins of the carapace will be
found to exhibit on each side a deep, nearly semicircular emargination, into which
the exognath of the second pair of maxillse fits. Moreover, this emargination is
bounded anteriorly as well as posteriorly by an oljtuse linguiform lobe bent inwards ;
the anterior lobe partly overlaps the body of the mandible, whereas the posterior
lobe inclines toward the base of the maxillipeds. Immediately anterior to the above
mentioned lateral expansion of the carapace, a strong spine projects in most of the species,
pointing obliquely forward, which, as to its position on the side of the basal part of the
antennae, may properlj"- be regarded as the antennal spine. Finally, just above the eyes,
or on each side of the base of the rostrum, the frontal i>aYt of the carapace usually juts
out into a similar, and often rather strongly developed spine, undoubtedly corresponding
to the supraorbital spine in other Podophthalmia.

The rostrum is generally rather elongate and slender, though sometimes very broad

REPORT ON THE SCHIZOPODA. 23

;it the base, spear-shaped, more or less straight and horizontally projecting, and
terminating in a sharp point. It has, also, three denticulate keels, one dorsal and two
lateral, a transverse section thus exhibiting a triangular form. Moreover, the dorsal
keel of the rostrum is produced posteriorly along the upper face of the carapace, being,
however, in some species interrupted in the middle part. It always reappears in the hind-
most region of the carapace, generally running out here as a more or less produced,
posteriorly directed, spine (the dorsal spine). The lateral wings of the carapace, too, in
some few species are i^roduced as similar posteriorly pointing spines, very highly
developed iu the form described below as Gnathophausia calcarata (see PI. IV.); in
most of the species, however, these parts are evenly rounded off.

The eyes in all known species are distinctly developed, although of somewhat
variable form, being sometimes very narrow, sometimes strongly dilated at the end, or
pyriform. Uu the upper side of the pedicle is invariably to be observed a small papillar
prominence (the ocular papilla). The eye-pigment is of a dark colour, and the visual
elements would seem to be normally developed.

The antennular peduncle (see PI. VIII. fig. l) is rather short and thick, though some-
what less so than in the two preceding genera. The basal joint is slightly flattened, and
]jrojects on the outer side at the apex as an obtuse bristle-beset angle. The second joint
is very short, almost discoidal, with an elevated crest running transversely over the upper
side. The last joint, almost square in form, exhibits internally a sharpened edge,
that runs out anteriorly as a linguiform lobe fringed with strong ciliated bristles. On
the upper side of this joint, as in the Mysidaj, between the insertion of the flagella,
occurs a small scale-like projection, furnished with three delicate diverging bristles.
Of the flagella, the inner one is rather narrow, filiform, and of moderate length. On the
other hand, the outer one is most remarkably developed, as a rule equalling the
whole body in length ; it is distinctly compressed throughout, indeed almost riband-
shaped, and furnished with a dense fringe of sensory bristles along one of its margins.

The basal part of the antennte (see Pis. II., III. fig. 4; PL IV. fig. 5; PI. V. figs. 4
and 9; PI. VI. figs. 3 and 9; PI. VII. figs. 3 and 8) is, as usual, rather thick and massive,
consisting of three segments, most distinctly defined below, the last of which runs out
externally as a compressed projection. The terminal pai't nearly equals in length the
inner antennular flagellum, its peduncle being rather small and divided into three
articulations, of which the last is the largest. The scale exhibits a somewhat difi"erent
appearance iu the difl"erent species. Thus, in the three species, Gnathophausia ingens,
Gnathophausia gigas, and Gnathophausia calcarata, it is very small and in form some-
what resembles that of Lophogaster, whereas in the remaining species its structure is
more in accordance with that usually met with in the Caridea.

The anterior lip (PI. IV. fig. 4, L; PI. VIII. fig. 2, L) forms a somewhat galeate or
triangular, fleshy prominence, placed posteriorly to the short epistome, at the anterior part

24 THE VOYAGE OF H.M.S. CHALLENGER.

of the buccal area, aud partly covering with its sharp posterior edge the masticator}^ parts
of the mandibles.

The posterior lip (PI. VIII. fig. 5) consists of two membranous and somewhat
expanded lobes, connate in the greater part of their length, and exhibiting anteriorly a
fringe of delicate cilia.

The mandibles (PI. IV. fig 4, M; PL VIII. figs. 2, 3) are strongly developed, with the
body evenly arched externally, and navicular in form. The cutting edge is armed with
strono- dentiform projections of a somewhat irregular form, and exhibits in its posterior part
a distinctly fluted molar surface. As is usually the case, the armature is some-what unequal
on the right and left mandibles (PI. VIII. fig. 2). The palp is rather large, densely setose,
and consists of three joints, the first quite short, the second comparatively elongate and
strongly compressed, the last rather narrow, and provided along the inner sharp edge,
almost throughout its whole length, with a dense fringe of delicate spines, disposed in a
pectinate arrangement, besides which it has a row of fine bristles (see fig. 3).

The first pair of maxillae (PI. VIII. fig. 6) exhibit, as in Lo2)hogaster, two incurving
masticatory lobes, of which the outer is the larger, and armed at the truncated apex with
short spines, whereas the inner lobe is more memliranous in structure, and densely beset
with ciliated bristles. These maxillaj, however, are readily distinguished by the presence,
on the outer side of the basal part, of a distinctly developed two-jointed palp, which,
contrary to what is the case in other Podophthalmia, is bent directly backward, so as to
project into the branchial cavity, thus acquiring at the first glance the appearance of an
epignath. Both joints of this palp are beset with long and thin l)ristles, of which more
especially those attached to the ovoid terminal joint are of very considerable length; all
these bristles are armed at one of their edges with fine spinules. Regarding the function
of this very peculiar palp, it certainly may be deemed similar to that observed in the
corresponding part of Cumacea and the cheliferous Isopoda, viz., to cleanse the branchial
cavity from foreign particles.

The second pair of maxillae (PI. IV. fig. 4, m^; PI. VIII. fig. 7) are rather large,
expanded into lamellfe, and exhibit exteriorly at the base a very conspicuous mamilliform
prominence (.r), within wliicli, in spirit specimens, is observed an opaque, finely granular
matter. As stated by the late Dr. v. Willemoes-Suhm, this prominence in fresh specimens
is vividly coloured, and has been regarded by that author as a kind of visual organ
(" accessory eye ") ; hence the generic denomination Gnathophausia. I have, however,
failed to trace any refracting elements within this prominence, and hence am in-
clined to regard it rather as a kind of phosphorescent organ. The basal part sends off
internally, as in Lophogaster, two masticatory lobes, pointing obliquely forward, of
which, however, the anterior is deeplj' cleft, almost to the base, forming two very
narrow lappets, provided, in addition to the usual apical spines, with a transverse row of
stiff bristles at some distance from the apex. The posterior masticatory lobe is rather

REPORT ON THE SCIIIZOPODA. 25

broader, linguiform, and provided along the inner margin with a double row of delicate
curving bristles. The distal portion of the basal part is marked off as a distinct segment,
furnished interiorly with a fascicle of bristles, whereas exteriorly, between the palp and the
exoguath, it runs out as an obtusely rounded jirominence. Tlie palp is comparatively
more strongly developed than in Lophogaster, consisting, as in that genus, of two distinctly
defined joints, the first of which is short and broad, the last oblong-ovate, and densely
fringed with bristles arranged along the inner edge in several rows. The exognath forms
a rather large ovate or elliptic lamella, attached exteriorly to the distal segment of
the basal part, and fringed with a dense row of very strong and elongate ciliated bristles,
all of which exhibit a distinct articulation near the base. This lamella, too, as stated
above, fits comparatively closely into the lateral emargination of the carapace at the side
of the buccal area (see PI. IV. fig. 4), forming, as it were, a kind of piston, by the
oscillatory movements of which the postero-anterior current of water produced beneath
the free portion of the carapace may ]:)e regulated.

The maxillipcds (see PL IV. fig. 4; PI. VIII. fig. 8) are rather short and thickset in
form, always closely applied to the other oral parts, which are partially covered by them
inferiorly. The basal part forms a rather strong transverse trunk, indistinctly divided into
two segments, and giving origin, at its anterior extremity, to the incurved terminal part
or palp, whereas, exteriorly, there is appended to the base a freely movable membranous
plate (ep) projecting within the branchial cavity, representing the epipodite. This
epipodite, as in Lophogaster, is of very considerable size, almost equalling in length the
whole maxilliped, and exhibits a narrow lanceolate form, the apex being somewhat
recurved. Its function, too, is more properly to produce by its rhythmical movements
to and fro, the current of water flowing beneath the free portion of the carapace, and
bathing the gill-branches attached outside the bases of the legs. The exopodite is
present only in four of tlie species, viz., Gnathophausia ingens, Gnathophausia gigci-s,
Gnathophausia calcarata, and Gnathophausia gracilis, as a very small narrow lingui-
form plate, fringed with ciliated bristles (see PI. IV. fig. 4). In the remaining species it
is, on the other hand, wholly wanting, and in its place may be observed a small
depression invested with a thickened glabrous cuticle (PI. VIII. fig. 8, .x), into wdiich
the above-mentioned mamillar prominence of the second pair of maxillaj would appear to
fit (see PL VIII. fig. 1 7). The terminal part, or palp, scarcely exceeds in length the
Ijasal, and is densely beset with bristles on both margins. It consists of five distinctly
defined joints, the third of which (carpus) is rather large and laminarly expanded. The
terminal joint (dactylus) is lanceolate, and at the inner edge finel)'' dentate. Of distinctly
developed masticatory loljes no trace can be found.

The first pair of legs (PL VIII. fig. 9) cUfier but very slightly in appearance from the
remaining ones, and cannot therefore be strictly regarded as true gnathopoda. The basal
section, contrary to what is the case in the maxillipeds, is exceedingly short, whereas the

(ZOOL. CHALL. EXP. PART X.XXVII. — 1885.) . Oo 4

26 THE VOYAGE OE H.M.S. CHALLENGER.

terminal part forms a very elongate five-jointed stem. Of the joints the carjjal, as in
the maxillipeds, is by far the largest, being even longer than the whole of the preceding
part of the leg. It is greatly compressed and somewhat expanded toward the end, being
fringed moreover at the distal part of the exterior edge with a row of very long,
anteriorly curving, ciliated bristles. The inner edge of this joint, too, is likewise
provided with several slender bristles, as also with a dense series of delicate curved
spinules, crowded together at the distal part. The succeeding joint (propodus), which, as
a rule, along with the carpal joint forms a strong geniculate curve, is likewise rather
elongate, but considerably narrower, somewhat curved, and densely setigerous, more
especially at the inner edge. The terminal joint or dactylus is narrow, lanceolate, and
armed at the inner edge with a dense row of small spinules, as also with a few elongated
bristles. The exopod, as in the succeeding legs, is developed into a powerful natatory
branch, on which can be distinguished a somewhat thickened and strongly muscular
l)asal part, together with a narrow and very flexible multiarticulate terminal part,
furnished on both edges with strong natatory setaj. At the base of this leg is attached
a fully developed gill of precisely the same structure as that characterising the five
succeeding pairs of legs. Projecting from the outer side of the basal part, may also be
observed a very small linguiform lobe, fringed with several exceedingly long and slender
divei-ging bristles. This lobe, which also occurs on the remaining legs (see fig. 10, ep),
would seem to represent a kind of rudimentary epipod.

The succeeding legs (see PI. VIII. figs. 10, 16) are all comparatively uniform in
structure, and very similar in appearance to the first pair, described above, differing
only in the carpal joint being somewhat less expanded and without the long ciliated
bristles at the outer edge, and also in the propodal joint being straighter and having the
bristles arranged in more or less distinct fascicles. This arrangement of the bristles
induced the late Dr. v. Willemoes-Suhm to describe the terminal portion of the legs as
subdivided into short articulations, as in the Mysidte, a character which, however, has not
been proved in reality to exist.

The legs, having all the character of true pereiopoda, as a rule diminish somewhat in
size posteriorly, likewise assuming, successively, a more slender form (see fig. 16). On
the last pair (fig. 14) the carpal and propodal joints become very narrow and of nearly
uniform length, both being furnished with numerous distinctly defined fascicles of
bristles. The terminal claw moreover is rather small and of a conical form.

The gills (see PI. VIII. figs. 16, 17) exhibit a rather complex structure, and occur
at the bases of all the legs. At the last pair, however (see fig. 14, hr), they are very
small and rudimentary, merely consisting of a single branch placed at the outer side.
On the other hand, all the remaining gills (six pairs in number) are of a perfectly
uniform structure, consisting of no less than four principal branches (see figs. 9, 11)
springing from a common base. Of these branches the largest, as in Lophogaster, is

REPORT ON THE SCHIZOPODA. 27

bent towards the ventral foce, where it is freely suspended, meeting the corresponding
branch on the opposite side in the median line (see fig. 16), whereas the remaining three
branches occur on the. exterior side of the legs and are completely covered by the
marginal portion of the carapace. Every gill-branch, too, consists of a median stem,
sending off in comparatively regular sequence secondary branches from each side,
whereby the whole branch acquires a bipinnate appearance. The secondary branches or
pinnulse are, furthermore, divided into a vast number of small lobes (see fig. 13) arranged
with less regularity, and even these lobes may occasionally be found, — especially on the
inner part of the gill-branch, — to be subdivided into smaller lobules. The final
ramifications of the gills are always of a simple cylindrical, or rather vesicular, form,
never, as in Lojjhogaster, foliaceous. Regarding the insertion of the gills, they would
seem to originate at the articulation between the bases of the legs and the pleuron of the
corresponding segment, and hence may properly be designated " arthrobranchise," although,
on dissection, they remain as a general rule in connexion with the legs.

In the fully developed females, as with Lophogaster, seven pairs of large foliaceous
lamellaj, fringed at the edges with bristles, spring from the bases of all the legs, and,
folding one over the other in the median line, form a capacious marsupial pouch, pro-
jecting from beneath the trunk (see PL .11. fig. 1 ; PL V. fig. 1 ; PL VL fig. 6).

In the males, on the other hand, may be observed, at the base of the last pair of leg.s
posteriorly (see PL VIIL fig. 14, p, and fig. 15) and on each side, a small tuberculiform
prominence, representing the outer sexual appendage, and having at its extremity the
fissure-like opening for the efferent duct of the testes.

The caudal limbs (PL VIIL fig. 18) in both sexes are developed in the same manner
as powerful natatory organs, consisting of a somewhat applanated and strongly muscular
basal part, and two very elongate and slender terminal branches, the outer part of which
is subdivided into a great number of small articulations furnished with strong natatory
setse. They aU exhibit a perfectly uniform structure, none of them in the males being
distinguished by the slightest peculiarity, as is the case in the Euphausiidae and Mysidse.

The telson (see PL II. fig. 7; PL IIL fig. 6; PL IV. fig. 7, &c.) is exceedmgly large,
and has the upper face somewhat channelled along the middle, exhibiting on each side an
obtuse longitudinal keel. It is slightly constricted near the base, and tapers more or
less rapidly toward the apex, which juts out into two strongly curved spines, connected in
the middle by a serrate lamella, thus forming together an almost semilunar projection.
The lateral edges of the telson are densely spinulous throughout their distal portion, the
spinules lieiug of somewhat unequal size, so that between two larger ones, as a rule,
occur a more or less considerable number of much smaller ones. At the base of the
telson, on the ventral face, is placed as usual the fissure-like anal opening.

The uropoda (ibid.) are generally shorter than the telson, and consist of an
exceedingly short basal part and two terminal plates, which admit of being spread out on

28 THE VOYAGE OF H.M.S. CHALLENGER.

either side, so as to form, along with the telsou, a com^jlete caudal fan. The outer plate
is the larger of the two, and has the outer edge rather arched in the middle, and
terminating posteriorly in a sliort dentiform projection, invariably placed at some
distance from the apex. From this projection, too, a distinctly marked transverse suture
passes obliquely across the plate, marking off the linguiform terminal portion of the
plate as a distinct joint, which, to a certain extent, would even appear to be movable by
the help of two thin muscles, proceeding to it from the proximal segment of the plate.
The whole of the interior border of this plate, as also the terminal lobe, is fringed with a
dense row of ciliated bristles. The inner plate is generally both somewhat shorter and
much narrower than the outer, and lanceolate in form, being also fringed around all
its borders with a row of similar bristles.

Nervous System. — The ventral chain of ganglia (see PI. VIII. fig. 19) is more
especially distinguished liy the very inconsiderable degree of centralisation observed in
the portion belonging to the anterior division of the body, exhibiting thereby a striking
resemblance to that in some lower forms of Crustacea, for example in Isopoda and
Amphipoda. The several ganglia are, on the whole, of a very uniform appearance, and
connected by rather long double commissures, their original twofold nature being also
distinctly perceptible. Exclusive of the cephalic or supra-oesophageal ganglion, nine
ganglia are found to belong to the anterior division of the body, and six to the posterior,
making in all fifteen different ganglia. Of these, only the two foremost (1-2), providing
the buccal parts with nerves, are partly coalescent, while all the rest are distinctly
definable. The commissures connecting the second and third ganglia are certainly very
short, leaving between them only a small rounded opening ; but the rest are of con-
siderable length and of distinctly fibrous structure. On the upper side of each of the
gangfia, counting from the fourth to the eighth, is observed a ligature-like, transverse
commissure (see fig. 20), arching over and holding in position the great ventral artery
{a) which, passing forward, sends off on each side immediately behind the ganglia a
lateral branch for the corresponding leg and its several appendages.

The ganglia of the tail (see fig. 19) are somewhat inferior in size to those of the trunk,
and are connected by much longer commissures, which, moreover, are placed close together.
The last caudal ganglion (G), occurring at the base of the caudal fim, is somewhat
larger than those preceding it, and sends off numerous nerves, some entering the telson,
some the uropoda, and finally innervates the muscles surrounding the anal opening.

Colour. — As has been stated by the late Dr. v. Willemoes-Suhm, all the specimens
examined by him belonging to this genus were, while still alive or in a fresh state, of a
vivid red colour, and in reality it is probable that this characteristic is common to all the
.species, a similar colour being likewise observed in several other deep-sea Crustacea.

Habitat. — All the species belonging to the present genus seem to be well marked
deep-sea forms. The least depth from which specimens have been obtained is

REPORT ON THE SCHIZOPODA.

255 fathoms {Gnathojihausia longispina), the greatest 2200 fathoms {G nathophcmsia
gigcis). Gnatho2^hcmsia has never been taken at the surface of the sea, although the
surface-net was in frequent use during the Expedition, both by night and day, and in many
different tracts of the ocean. It may therefore certainly be assumed that these
Crustacea, notwithstanding their strongly developed natatory organs, never leave the
deeper strata of the sea, and that in all probability they have their habitat on the sea-
bottom itself.

To judge from the inconsiderable number of examples of each species obtained by the
Expedition, notwithstanding that a large trawl-net was generally in use, it would appear
that the animals of this genus lead a comparatively isolated existence, being seldom met
with in shoals.

Distribution. — The genus seems to exhibit a very extensive geographical distribution,
being most probably represented throughout the greater part of the ocean, excepting
perhaps the Arctic and Antarctic regions. Thus, as will be shown in the sequel, species of
this genus have Ijeen recorded both from the North and South Atlantic, from the Pacific,
and from the seas of the Indian Archipelago. The genus may even be reckoned
among the European fauna, one of its species {G nathophausia zo'ea) having been found by
the French expedition in the Bay of Biscay.

Classification. — The species may be naturally classed within two or rather three
sections or subgenera, chiefly characterised by the form of the antennal scale, the presence
or absence of an exopodite on the maxillipeds, and finally by the form of the carapace.

The following synopsis of the species may be here appended : —

Antennal
scale

very small, not
jointed, outer
margin serrate.
Rostrum

Synopsis of the Species of Gnathophaxisia.

short, indistinctly denticulate, ....

{ slightly produced,
elongate. Infero-posterior )

corners of carapace '\ produced as long ser-

rate spines,

large, of usual
form, jointed,
outer margin
terminating in
a strong spine.
Inferoposterior
corners of cara-
pace

rounded
off. Dor-
sal spine

compara-
tively short.

Upper
lateral keel

greatly pro-
duced. An-
tennal scale
with spine
of the outer

distinct.

Epimera
of the
caudal

segments

obsolete,

sharply
pointed,

obtuse, .

of moderate size,

greatly produced and
serrate on both
margins.

produced into two distinct spines,

G. ingens, Dohrn.
G. gi'jas, Sulim.

G. calcarata, G. 0. Sars.

G. teillemoem, G. 0. Sars.
G. affinis, G. 0. Sars.

G. elegans, G. 0. Sars.

G. zoea, Sulim.

G. longispina, G. O. Sars.
G. gracilis, Suhni.

80 THE VOYAGE OF H.M.S. CHALLENGER.

Section 1. — Infero-posterior corners of carapace produced into sharp points more or less
elongated. Dorsal spine short or obsolete. Dorsal keel of carapace interrupted in the
middle part. Supra-orbital spines small or obsolete. Antennal scale small, not jointed,
outer margin serrate. Maxillipeds with a small exopodite. Epimeral spines of the last
caudal segment confluent on the ventral face, forming together a cordiform concave plate,
incised at the apex.

3. Grnathophausia ingens (Dohrn) (PL II.).

Lophogaster ingens, Dohrn, Untersuchungen iiber Bau und Entwickeliiiig der Arthropoden,
Zeitschr. f. wiss. Zool, Bd. xx. p. 610, pi. xx si figs. 12-14, 1870.

Gnatlwphausia injfata, Suhm, MS.

Gnathophausia ingens, G. O. Sars, Preliminary Notices on the Challenger Schizopoda,
No. 3.

Specific Characters. — Form of body rather robust, the anterior division (in the female)
greatly inflated. Carapace large, with the infero-posterior corners produced into small
slightly curved spines. Dorsal spine very short, almost obsolete. Eostrum short, very
broad at the base, indistinctly denticulate. Supra-orbital spines wanting; antennal spines
small but distinct; branchiostegal spines obsolete. Eyes with rather long and narrow
pedicles, cornea somewhat expanded. Antennal scale very small, subovate, apex truncate,
outer edge minutely serrate in the distal half Caudal segments distinctly sculptured,
both lappets of the epimera pointed. Epimeral plate of last segment large and deeply
•cleft at apex. Telson much longer than uropods; its lateral edges evenly arched.
Length, 157 mm.

Remarks. — The present gigantic Schizopod had already laeen described and figured
by Professor A. Dohrn in the year 1870 from a somewhat defective specimen sent him from
the Zoological Museum of Hamburg. Notwithstanding that all the legs in his specimen
had been broken, Professor Dohrn was yet able to recognise it as a true Schizopod, most
nearly approximating to Lopliogaster ; and he described it as a new species of the genus
under the name of Lophogaster ingens. The examination of the specimen procured by
the Challenger Expedition, which is comparatively well preserved, fully confii-ms this view,
so far as regards the Schizopod nature of this form and its relationship to Lophogaster.
On the other hand, it cannot at present be strictly referred to the last mentioned genus,
but is to be regarded as a true Gnathophausia. This view was also suggested by the
late Dr. v. Willemoes-Suhm, who, in his manuscript notes, has mentioned this form
under the name of Gnathophausia injiata, n. sp. The specific denomination ''ingens"
proposed by Dohrn having, however, been given prior to the Challenger Expedition,
must of course be retained for the species.

Description. — The specimen obtained by the Challenger Expedition is a fuU-grown

REPORT ON THE SCHIZOPODA. 31

f«;male, with enormously developed marsupial pouch, from which apj)areiitly the young
had just emerged.

The length of the body, measured from the tip of the rostrum to the extremity of
the telson, is 157 mm., a truly gigantic size for a Schizopod ; and this form ranks
therefore as the largest by far of all hitherto known Schizopods. The specimen
examined by Professor Dohrn was likewise very large, measuring 155 mm. in length.

The general form of the body (see figs. 1 and 2) is comparatively rather clumsy and
thickset, the anterior division being very massive and greatly inflated, and fully attaining
the leno-th of the tail.

The integuments are throughout rather soft and flexil)le, exhibiting, as it were, a
parchment-like consistence.

The carapace is of very considerable size, completely covering the whole of the
anterior division of the body, and even somewhat overlapping at the sides the first caudal
segment. It is, too, evenly arched above and rather broader thnn high. The two lateral
keels are somewhat prominent ; on the other hand, the dorsal carina is wholly efikced in the
middle of the carapace, being distinct on the rostral part only, and far behind, where it
terminates in a very short pointed projection, or a rudiment of the dorsal spine.
Between the anterior part of the two upper lateral keels is seen the linguiform dorsal
area (see fig. 2), which only reaches to about the middle of the length of the carapace.
The rostrum is comparatively short, but very broad and massive at the base, and forms a
horizontal, triangular projection, protruding from the anterior part of the carapace, and
partly covering the antennular peduncles and the inner part of the ocular pedicles.
It terminates in a sharp point, and exhibits but very faint traces of the usual denticles,
which in other species are to be found both on the dorsal and the lateral keels. Of
supra-orbital spines, no trace whatever can be detected. On the other hand, the antero-
lateral corners of the carapace jut out as distinct, though rather small, antennal spines;
and slightly posterior to each spine may be observed a small projection, representing
a rudiment of the branchiostegal spine. Posteriorly, the carapace forms in the middle a
rather deep emargination, embracing here, as it were, the first caudal segment. The
infero-posterior corners (see fig. 1) are produced as very short spines, curving somewhat
upward, and the posterior margin of the carapace forms on either side immediately above
this spine an evenly arched curve. Moreover, at some distance from the edge may be
observed two parallel elevated lines, connecting the two lateral keels, and these are also
continued above to the dorsal carina.

The tail, as in the other species of the genus, is very slender and almost cylindrical in
form, though somewhat flattened above. It exhibits a very conspicuous sculpture,
consisting of numerous irregularly flexuous impressions, limited by elevated lines, giving
to that part a peculiarly wrinkled appearance. Its • segments are nearly of uniform
length, but diminish somewhat both in height and breadth posteriorly. The epimera

32 THE VOYAGE OE H.M.S. CHALLENGER.

arc distinctly developed and almost perpendicular, projecting into two acutely pointed
lappets, of which the posterior is the larger and is provided with an elevated keel.

The last segment, as in the other species, is divided by an obliquely transverse
suture into two sections, the anterior of which juts out on either side into an cpimeral
projection, which unites on the ventral face with the corresponding one on the opposite
side, forming together a large cordiform plate, concave in the middle and cleft at the
apex into two slender, bidentate lappets, reaching even somewhat beyond the extremity
of the segment (see fig. 6).

The eyes (fig. 3) are more especially distinguished by the considerable length of
the pedicles, which are very narrow, and apparently consist of two segments, the external
one exhibiting above a small papillary projection. The cornea is rather expanded and
somewhat oblique, occupying, however, l:)ut a comparatively small part of the eye itself.

The antennular peduncle (see figs. 1 and 2) is verjr short and thick, scarcely reaching
beyond the eyes when they are extended. The flagella, too, were partly defective in
the specimen examined.

The antennal scale (see fig. 4) is comparatively very small and of an oval form, the
extremit)^ being truncated or very slightly emarginate, with the inner corner a little
more prominent than the outer. The outer edge is somewhat arched, and, in its distal
half, armed with" about six very small and inconspicuous teeth. The inner edge, too,
is almost straight, being rather strongly arched in its hindmost part; it is fringed
throughout with a dense row of comparatively short l)ristles.

The oral parts, so far at least as they admit of being examined without dissection,
would seem on the whole to agree perfectly with those in the two succeeding species.
As in the latter, the maxillipeds are provided with a distinct though very small lamelli-
form exopodite.

The legs (fig. 5) are comparatively rather robust in structure and densely setigerous
on both margins, the carpal and propodal joints being strongly compressed and the
dactylus rather small.

The incubatory lamellfe, composing the marsupial pouch, are, in the specimen treated
of here, exceedingly large, of an oblong-ovate form, and densely setose at the edges,
forming together a very conspicuous, convex jjrominence beneath the trunk (see fig. 1).

The telson (see fig. 7) is very large and massive, equalling in length the three
preceding segments taken together. The outer part tapers successively toward the apex,
and has the lateral edges but slightly arched and "armed with a vast number of fine
spinules. The two falciform apical spines are, as usual, confluent at the base, forming
together a semilunar projection appended to the apex of the telson, with its posterior
concave margin finely serrate.

The uropoda {ibid.) are much shorter than the telson, but otherwise exhibit the
structure characteristic of the senus.

REPORT ON THE SCHIZOPODA. 33

Habitat. — The above described specimen was obtained l)y the Challenger Expedition,
in the vicinity of the Arrou Islands, in the Arafura Sea, lying between New Guinea and
Australia.

Station 191, September 23, 1874 ; lat. 5° 41' S., long. 134" 4' 30" E.; depth, 800
fathoms; green mud; bottom temperature, 39°'5.

The specimen examined by Professor Dohrn, according to the label on the bottle
containing it, was procured off the coast of Africa (" Laos ") ; depth not recorded.

^ 4. Gnathojyhaiisia gigcis, Willemoes-Suhm (PL III.).

Gnathophausia gl{jas, Suhm, Trans. Linn. Soc. Lond. (Zool.), .«or. 2, vol. i. p. 28, pi. ix.

figs. 16, 17; pi. X. figs. 2, 3, 1875.
Gnathophausia ijigas, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 4.

Specific Characters. — Form of body (in male) rather more slender than in the last
species. Carapace less tumid, having the infero-posterior corners more produced and
jutting out into short mucroniform spines, reaching to the end of the second caudal
segment. Dorsal spine almost obsolete. Rostrum rather produced and slender, distinctl}-
denticulate. Supra-orbital, antenna!, and branchiostegal spines all distinct but small.
Caudal segments less distinctly sculptured, the anterior lappet of the epimera small and
I'ounded. Epimeral plate of last segment less produced. Eyes narrow, with coi'nea
very small. Antehnal scale much larger than in Gnathophausia ingens, and somewhat
tapering toward the apex, outer edge divided into four strong teeth, inner corner
produced into a rather prominent sharp point. Telson very large, with the lateral
margins bulging out in the middle and densely spinulose, terminal spines widely
diverging. Length, 142 mm.

Remarks. — The present species has abeady been briefly described and figured by the
late Dr. v. Willemoes-Suhm in the above quoted treatise, and designated by the specific
name of " gigas," the preceding still larger form not being known to him at that date.
From this latter species it differs, among other characteristics, by the comparativel}'
more slender form of the body, the much more produced rostrum, the larger and
differently formed antennal scale, and the less completely developed eyes. Moreover,
the spines, issuing from the infero-posterior corners of the carapace, are somewhat
different in shape, and the sculpturing of the tail is by no means equally conspicuous.

Description. — Of this species, also, only a solitary specimen in an excellent state of
preservation was obtained, viz., a full-grown male, measuring in length 142 mm. As
the males of this genus differ l)ut very slightly from the females, it may not unreasonably
be inferred that the characters adduced above as specific marks would, on the whole, be
no less applicable to the females of this species.

The form of the body (see figs. 1, 2) is rather more slender than in Gnathophausia
ingens, Ijut in this respect, probably some regard should l)e paid to the circumstance

(zool. chall. EXP. — PART WWII. — 1885.) Oo 5

34 THE VOYAGE OF H.M.S. CHALLENGER.

that the specimen under treatment is a male, while that representing the preceding
species is a female.

The integuments are throughout very thin, and in the spirit specimen semi-
diaphaneous, so as to admit of the muscular system being distinctly traceable through
the skin.

Here, too, the carapace covers the whole of the anterior division of the body, but is
far from being so inflated as in Gnathophausia ingens, its breadth scarcely exceeding
its height. The lateral wings are com2Daratively more produced, and terminate in a
perfectly straight, mucroniform spine, reaching as far as the end of the second caudal
segment. The keels of the carapace, as also the dorsal area, exhibit precisely the same
appearance as in the preceding species. On the other hand, the rostrum would seem to
have been much more produced, though I cannot myself state its length with exactness,
the point having been broken off in the specimen. To judge, however, from the form of
its basal part still remaining, it may certainly be inferred to have been at least much
more elongate than in Gnathophausia ingens, and in the figures given by the late
Dr. V. Willemoes-Suhm, which were drawn from the recently taken and uninjured specimen,
it is in reality represented as being more than half as long as the carapace, and also distinctly
denticulate throughout.^ There is, contrary to what is the case in the preceding species, a
distinct, though rather small, supra-orbital spine on either side of the base of the rostrum.
Moreover, both the antennal and the brauchiostegal spines are distinctly marked.

The caudal segments do not exhibit the peculiar wrinlded sculpture distinguishing
this part in Gnathophausia ingens, only a slight transverse impression being observable at
each extremity. On the epimera, too, the anterior lappet is very short, and rounded at
the apex, not pointed as in that species. Here, also, the epimeral projections of the last
segment are confluent on the ventral face, forming together a cordiform concave plate
(see fig. 5), but this is much shorter than in Gnathophausia ingens, and its apical
indentation broader.

The eyes (fig. 3), as in Gnathophausia ingens, are very narrow, but the cornea is
much smaller and scarcely expanded at all ; moreover, the ocular papilla is situated closer
to the base of the pedicle.

The antennular peduncle (see fig-s. 1, 2) is greatly thickened, with the second
joint exceedingly short, and almost discoid. The outer flagellum is indeed enormously
developed, even exceeding in length the whole body, being also very strong and distinctly
riband-shaped. The inner flagellum is much more slender, and about the same length as
the carapace, exclusive of the rostrum.

The antennal scale (fig. 4) considerably exceeds in size that of the preceding species,
and also exhibits a rather different form, tapering somewhat toward the apex, the inner

' In PI. in. figs. 1 and 2 given in the present Report, the missing part of the rostrum has been added after the
drawings of Dr. v. AVillemoes-Suhm.

REPORT OX THE SCHIZOPODA. 35

corner of which is drawn out to a very prominent and sharply pointed projection.
The outer edge is, moreover, divided into four strong teeth, somewhat increasing in size
toward the apex ; and between the last of these and the inner corner, the edge of the
scale is evenly emarginate. The flagellum about ecjuals in length the inner antennular
flagellum.

The oral appendages and the legs do not seem to exhibit any essential difference
from the same limbs in Gnathophausia itigens.

On the other hand, the caudal limbs appear to be somewhat more strongly developed,
but this may arise from the circumstance that the specimen treated of is a full-
grown male.

The telson (see fig. 6) is of very considerable size, even surpassing in length the three
preceding segments taken together. In form it agrees very closely with that of the
preceding species, differing only in the lateral edges being somewhat more abruptly
arcuate in the middle, and in the marginal spinules being comparatively coarser. The
apical spines (see fig. 7) are widely divergent, and are furnished near the point on the
outer side with a small tooth ; the evenly concave margin connecting both spines is
finely and regularly serrate.

The uropoda (ibid.) seem to l)e a little more elongate than in Gnathophausia ingens,
but in other respects exhibit a very similar appearance.

Habitat. — -The specimen described above was taken in the North Atlantic, west of
the Azores, at a very considerable depth.

Station 69, June 25, 1873 ; lat. 38° 23' N., long. 37° 21' W.; depth, 2200 fathoms;
Globigerina ooze ; bottom temperature, 36°'2.

Exclusive of this specimen, I also found among the material placed in my hands for
examination the recently moulted skin of the outer part of the tail of another specimen,
apparently belonging to the same species. This skin was brought up along with speci-
mens of Boreomysis scyphops, in the Southern Ocean, between Kerguelen and Australia.

Station 157, March 3, 1874 ; lat. 53° 55' S., long. 108° 35' E.; depth, 1950 fathoms ;
Diatom ooze; bottom temperature, 32°"1.

Hence the species seems to exhibit a rather extensive geographical distribution, its
occurrence in both hemispheres having been ascertained.

5. Gnathophausia calcarata, G. 0. Sars (PI. lY.).

GnathopJiausia (jigas, var., Sukm MS.

Gnathophausia calcarata, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, Ko. 5.

Specific Characters. — Integuments rather finu. Carapace with a well marked,
although somewhat short, dorsal spine, projecting from the middle of the posterior
margin, the infero-posterior corners produced into very long and slender, finely serrate

36 THE VOYAGE OF H.M.S. CHALLENGER.

spines. Rostnim strong, of about the same length as the carapace, distinctly denticulate.
Supra-orbital spines obsolete, antennal and branchiostegal spines well defined, the latter
remarkably strong and finely serrate, pointing outward. Caudal segments sculptured
with transverse impressions, epiraera produced into two acuminate lappets of nearly equal
size. Eyes pyriform, cornea rather expanded. Antennal scale very small, ovate, outer
margin slightly serrate, apex obliquely truncate, inner margin arcuate. Telson large,
with the terminal spines crescent-shaped and denticulate along the upper face. Uropoda
much shorter than telson. Length of largest specimen (which had probably reached its
maximum size) 98 mm.

Remarks. — This form has been preliminarily recorded by the late Dr. v. Willemoes-
Suhm, in his manuscript notes, as a variety of G)iathophausia gigas. It should,
however, be certainly regarded as a distinct species, though closely related to the two
preceding ones. From Gnathophausia gigas it may, among other characteristics,
be readily distinguished by the unusually firm integuments, the distinctly marked dorsal
spine, and the remarkably long spines issuing from the infero-posterior corners of the
carapace, a character which has given rise to the specific denomination "calcarata."
Futhermore, the rostrum is much coarser in structure, and the branchiostegal spines
considerably more developed ; while, as a final distinction, the eyes and the antennal scale
are of a somewhat different form.

Description. — Of this handsome species there are two well preserved specimens in the
collection, both males. The largest specimen has a length of 98 mm.; the other is rather
smaller in size, the length being only 68 mm. These two specimens exhibit, it would
seem, some difterence as regards the length of the rostrum and the lateral spines of the
carapace, l3ut in all other respects agree perfectly with each other.

The general form of the body (see figs. 1, 2) closely approximates to that of
Gnathopha^isia gigas, though perhaps a trifle more robust.

The integuments are throughout very much firmer than in either of the two preceding
species, and apparently they are somewhat indurated, giving to all the parts of the body
a more solid and distinctly defined appearance.

The carapace, although rather large, does not cover the trunk to the same extent as
in the two preceding species, the last segment being partly exposed behind the posterior
margin. Both the lateral keels are strongly prominent, whereas the dorsal keel, as in
the former species, is distinct in the anterior and posterior parts only, being quite obsolete
in the middle of the carapace. The dorsal spine, projecting from the middle of the
posterior margin, is well marked, though not attaining any considerable length. On the
other hand, the spines projecting from the infero-posterior corners of the carapace are
remarkably elongate and slender, mucroniform, and somewhat diverging, being finely
serrate at the edges. In the smaller specimen (see fig. 3) these spines are much produced,
reaching even to the end of the third caudal segment ; in the larger one (figs. 1, 2) they

REPORT ON THR SCHIZOPODA. 37

are somewhat shorter, but, in other respects, of very similar a[)pearance. As in
Gnathophausia ingens, two distinctly elevated lines may be observed a short distance
within the posterior margin of the carapace, running parallel to the edge. The rostrum
is strongly developed, and rather produced, in the smaller specimen (fig. 3) being about as
long as the carapace, in the larger (figs. 1, 2) somewhat shorter. It extends, as usual,
horizontally, and is three-edged and distinctly denticulate throughout, terminating in a
sharp point. The supra-orbital spines would seem to be wanting, or at least are very
inconspicuous, the slight projections seen at the base of the rostrum (fig. 3, a) being
simply a pair of the lateral rostral denticles placed at some distance posterior to the
others. On the other hand, the antennal spines (6) are very distinctly marked, and the
branchiostegal spines (c) distinguished by very considerable size, jutting out on either
side as a pair of strong, denticulated processes.

All the caudal segments exhibit, at some distance from the posterior margin, a
rather deep transverse impression, and, in addition to this characteristic, are very shai-ph'
defined, the one from the other. As in Gnathophausia ingens, both lappets of the
epimera are acutely pointed and somewhat produced, the anterior being a trifle smaller
than the posterior. The epimeral spines of the last segment (see fig. 6) in this species
are also partly connected on the ventral face, and are rather smaller than in the tw^o
preceding species, the terminal indentation between their outer parts being also shorter
and broader.

The eyes (see figs. 1, 2, 4) are slightly dilated toward the apex, almost clavate in
form, the cornea being more expanded than in the preceding species.

The outer flagoUum of the antennulse (see figs. 1, 2) is remarkably strong, and about
equal in length to the whole body, the rostrum excepted.

The antennal scale (see figs. 4, a, 5) is comparatively very small, and ovate in form,
somewhat resembling that of Gnathophausia ingens. Its apex, however, is here obliquely
truncate, not emarginate, and the inner corner is rather more prominent than in that
species. The outer edge exhibits in its distal part five or six somewhat unequal and
rather small teeth, and the inner setigerous edge is more evenly curved than in
Gnathophausia ingens.

The oral parts (see fig. 4), the legs, and the caudal limbs would seem on the whole
to agree perfectly with the same parts in the two preceding species, save, perhaps, that the
legs are somewhat more robust in form and less elongate.

The telson (see fig. 7), as in the two preceding species, is very large and massive, about
equalling in length the three preceding segments taken together, and it gradually tapers
toward the apex, the lateral edges being evenly arched, and armed with a large number
of small spinules. The two apical spines, connected as usual in the middle, form a com-
paratively regular crescent-shaped projection, finely serrate at the bottom of the posterior
emargination, and, moreover, exhibiting on the upper face a row of small denticles.

38 THE VOYAGE OF H.M.S. CHALLENGER.

The uropoda (ibid.) are much shorter than the telson, and have a somewhat similar
form to those in Gyiathophausia ingens.

Habitat. — Of the two specimens obtained by the Challenger Expedition,, the larger
was taken, along with the above described specimen of Gnathophausia ingens, in the
Arafura Sea.

Station 191, September 23, 1874; lat. 5° 41' S., long. 134° 4' 30" K; depth,
800 fathoms; green mud; bottom temperature, 39° '5.

The other specimen was obtained in the vicinity of the Talaur Islands, south of
Mindanao (Philippines).

Station 214, February 10, 1875; lat. 4° 33' N., long. 127° 6' E.; depth, 500 fathoms;
blue mud; bottom temperature, 4l""8.

Hence the geographical distribution of this species, so far as is at present known,
ranges within the seas of the East Indian Archipelago.

Section 2. — Infero-posterior corners of carapace rounded off. Dorsal spine produced.
Dorsal keel uninterrupted in the middle. Supra-orbital spines distinctly defined from the
rostral part of carapace, and rather large. Antennal scale of the form usually met with
in the Caridea, jointed at the extremity, outer edge jutting out anteriorly as a more or
less produced spine. MaxiUipeds without any trace of exopodites. Epimeral spines of
last caudal segment not confluent on the ventral face.

6. Gnathophausia ivillemoesH, G. 0. Sars (PI. V. figs. 1-6).

G-nathophausia zoea, var.^ Suhm MS.

Gnathophaiisia loillemoesii, G. O. Sars, Preliminary Notices ou the Challenger Schizopoda,
No. 6.

Specific Characters. — Form of body rather robust. Carapace covering whole of trunk,
with the dorsal spine comparatively short, projecting only a little beyond the first caudal
segment. Eostrum shorter than carapace, very narrow, and provided with small denticles
comparatively few in number. Supra-orbital spines very strong, anteriorly curved ; antennal
spines distinct; branchiostegal spines obsolete. Five anterior caudal segments keeled
above, and produced posteriorly into short but distinct dorsal processes; posterior lappet
of epimera lanceolate. Eyes pyriform. Antennal scale rather large, only twice as long
as broad, terminal lobe but slightly projecting beyond the spine of the outer corner.
Telson linguiform, lateral margins evenly curved and densely spinulous; aj^ical S23ines
rather short, serrate at the posterior margin. Uropoda somewhat shorter than telson.
Length 136 mm.

Remarks. — In his manuscript notes the late Dr. v. Willemoes-Suhm has recoi'ded,

REPORT ON THE SCHJZOPODA. 39

with a certain amount of hesitation, this form as a variety of Gnathophausia
zoea. In my opinion, however, it should decidedly be regarded as a distinct species,
although belonging to the same section of the genus as that species. From
Gnathophausia zoea (see PI. VI. figs. 6, 7) it may at a glance be distinguished
by the far inferior development of both the dorsal spine and the rostrum, by the
different form of the antenual scale, and finally by its much greater size.

Description. — There are two specimens of this species in the collection ; one of
very considerable size, reaching a length of 136 mm. This is a female, with distinctly
developed incubatory lamellae. The other specimen is somewhat smaller, and would
seem to be a male, as no trace of incubatory lamellse can be discerned, but in other
respects it agrees perfectly with the first named specimen.

The form of the body (see figs. 1, 2), as compared with that of the other .species
belonging to this section, is rather robust, the anterior division being unusually massive
and thickset.

The integuments are not very firm, though somewhat more so than in Gnaihop>hausia
ingens and Gnathophausia gigas.

The carapace is rather large, covering the whole of the trunk, none of the segments
of the latter being exposed. It is evenly arched above, and about as broad as high.
Both the lateral keels are distinctly marked, though by no means so prominent as in
Gnathophausia calcarata. The dorsal keel in this species does not experience any
interruption whatever, being continued along the whole back of the carapace, and running
out posteriorly as a strong mucroniform projection — the dorsal spine. This spine, too, is
decidedly glabrous, and does not attain any considerable length, projecting but slightly
beyond the first caudal segment. As in the other species belonging to this section, the
' infero-posterior corners of the carapace are evenly rounded off, without any trace of the
spine occurring here in the three preceding species. Moreover, the lower lateral keel,
which in these species runs out into the said spine, in this animal curves upward Ijcfore
reaching the margin, and joins the upper one at the base of the dorsal spine. Close to
the posterior mai'gin another elevated line may be seen, w^hich, in connexion wiih. the above
mentioned continuation of the lateral keel, marks off" a slight groove, running parallel
to the posterior edge of the carapace. The rostrum is exceedingly slender, and does not
seem to attain the length of the carapace. The point in Ijoth specimens, however,
having been broken off", its length cannot be stated with perfect accuracy. It is very
slightly curved, and exhibits in its distal part a few small denticles, arranged dorsally as well
as laterally, the jjroximal part being wholly unarmed. The supra-orbital spines are distinctly
marked off" from the rostrum, jutting out as two very strong, anteriorly curving, and
acutely pointed, projections, to either side from the frontal part of the carapace, partly
covering the bases of the eyes above. The antennal spines, too, are rather well defined and
somewhat diverging. On the other hand, the branchiostegal spines are quite absent,

40 THE VOYAGE OF H.M.S. CHALLENGER.

their place being occupied by the roimded lateral expansions of the carapace to the sides
of the buccal area .

Of the caudal segments, the five anterior ones are distinctly keeled along the middle of
the dorsal face, and jut out at the posterior margin into short jsosteriorly pointing spines.
The epimera are rather small, and the anterior lappet is almost obsolete, whereas the
posterior is somewhat produced and acutely pointed. The epimeral spines on the last
segment are comparatively small, and do not, as in the preceding species, unite on the
ventral face, being on the contrary, separated by a distinct interstice (see fig. 5).

The eyes (fig. 3) are rather short and pyriform, the cornea being greatly expanded,
and occupying a considerable part of the eye. The ocular papilla is very small, and
placed about the middle of the pedicle.

The antennulse (see figs. 1, 2) exhibit the usual structure, the peduncle being short
and thick, and the outer flagellum strongly developed, almost equalling in lengtli the
whole body.

The antennal scale (fig. 4), on the other hand, does not show any resemblance to that
in the three preceding species, being more in accordance with the structure usually met
with in the Caridea. It is rather larg-e and oblono-ovate in form, about twice as Ions; as
broad, with the inner edge very considerably arched in its proximal part, the outer
almost straight, and running out into a strong, anteriorly pointing, spine. The terminal
part of the scale forms a linguiform lobe, projecting a little beyond the said spine, and
frinsjed throughout with a dense row of ciliated bristles, which is also continued alonof
the whole internal margin of the scale. From the base of the above mentioned spine, a
distinctly marked suture passes, in an obliquely transverse direction, across the scale,
dividing it into two segments, which to a certain extent will admit of being moved towards
each other, a fascicle of short muscles joining the suture posteriorly.

The oral parts do not seem to exhibit any essential difference from those in the
preceding species, except that, as in all the species belonging to this section, the
maxillipeds are found wholly destitute of the exopodites.

]\Ioreover, the legs and caudal limits are of a very similar structure.
The telson (fig. 6) is rather large, though perhaps less massive than in the three
preceding species, and exhibits a comparatively regular linguiform shape, the lateral
margins being evenly arched in theii- distal part, and armed -wdth numerous delicate
spiuules arranged in the usual manner. The apical spines are rather small, forming-
together, as in the other species, a crescent-like projection, finely serrate along the evenly
concave posterior margin.

The uropoda (see figs. 1, 2), as in the other species belonging to this section, are
rather larger than in the three preceding ones, reaching almost to the tip of the telson,
when extended posteriorly ; tlieir structure, however, is very similar to that in the above
mentioned species.

REPORT ON' THE SCIIIZOPODA. 41

Habitat. — The two specimens of this species procured by the Challenger Expedition
were taken in the same locality, south of Araboina, in the Banda Sea.

Station 195, October 3, 1874; lat. 4' 21' S., long. 129° 7' E. ; depth, 1425 fathoms;
blue mud : l)ottom temperature, n8°'0.

7. Gnathophaitsia affinis, G. 0. Sars (PI. V. figs. 7-10).

G-nathophausia affinis, G. C). Sars, Preliminary Notices on the Challenger Schizopoda, No. 7.

Specific Characters. — Form of bodv more slender than in the last species. Carapace
comparatively small, not covering completely the last segment of the trunk. Dorsal
spine rather short, not projecting beyond the first caudal segment. Rostrum shorter
than carapace, exhibiting a very close and delicate armature of small denticles, continued
above to its very base. Supra-orbital spines not very strong, and somewhat diverging ;
antennal and branchiostegal spines inconspicuous. Caudal segments not keeled above,
nor provided with dorsal processes ; posterior lappet of epimera rounded at the tip.
Antennal scale narrower than in Gnathophaumi ivillemoesii, its terminal lobe greatly
surpassing the spine of the outer corner. Telson and uropoda nearly the same as in
Gnatliophausia loillemoesii. Length, 81 mm.

Remarks. — This species is very closely allied to Gnathophausia willemoesii, but
apparently distinct, diff"ering, among other characteristics, in the form and armature
of the rostrum, the much smaller supra-orbital spines, and the absence of distinctly defined
antennal spines ; the caudal segments, moreover, are not keeled above, as in that species,
and they have the posterior lappet of the epimera rounded at the tip.

Description. — The solitary specimen procured, and erroneously referred by the late
Dr. V. Willemoes-Suhm to Gnathophausia zoea, is a female, with distinct though rather
small incubatory lamellge. It measures 81 nun. in length.

The form of the bod}- (see figs. 7, 8) is somewhat more slender than that of
Gnathophausia willemoesii, the anterior division i»eing far less tumid than in
that species.

The carapace does not completely cover the trunk, the last segment of which appears
in part exposed behind its posterior margin. Both lateral keels are distinctly marked,
but the lower one disappears at a short distance within the infero posterior corners
of the carapace, without, as in Gnathophausia willemoesii, being continued upwards.
The dorsal keel, too, is, as in that species, distinctly marked along the whole Ijaek of
the carapace, though a small impression may be seen above, at a short distance behind
the rostrum. The dorsal spine is rather short, not reaching beyond the first (;audal
segment. The rostrum does not attain the length of the carapace, but is somewhat
coarser in structure than that of Gnathophaxisia ivillemoesii. It is closely armed
with a very considerable number of exceedingly small denticles, continued along

(ZOOL. CHALI.. EXr. — PART X.XXVH. — 188.5.) Oo G

42 Till!: VOYAGE OF H.M.S. CHALLENGER.

tLe dorsal crest, and even a short distance back on its base. The supra-orbital spines
are rather smaller than in Gnathophausia ivillemoesii, and more divergent, scarcely
projecting beyond the eyes. No distinct antennal nor branchiostegal spines are present,
the lateral expansions of the carapace forming in lieu thereof only two slight angular
projections.

The ■ caudal segments do not exhibit any trace of a dorsal keel, nor does their
posterior margin form any dorsal projections. The epimera are very small, scarcely
projecting even beyond the ventral face, and their posterior lappet is obtusely rounded at
the tip.

The eyes are nearly of the same form as in Gnathojyhausia ivillemoesii.

The antennal scale (see fig. 9) is rather large, but comparatively not so broad as in
the preceding species ; its terminal lobe, too, is more produced, and projects very
considerably beyond the spine of the outer corner.

As regards the oral appendages, the legs, and the caudal limbs, I need not dwell on
the description of these parts, as they are much the same in all species belonging to this
section.

Moreover, the telsou and uropoda (see fig. 10) do not exhibit any essential diiference
from the same parts in Gnathophausia willemoesii, excepting, perhaps, that the lateral
margins of the telson are somewhat more strongly arched in the distal part, and that the
apical spines have a short denticle at the outer edge.

Habitat. — The specimen described above was taken in the tropical part of the
Atlantic, almost midway between Africa and Brazil.

Station 107, August 26, 1873; lat. 1° 22' N., long. 26° 36' W.; depth, 1500 fathoms;
(jtlobigerina ooze; bottom temperature, 37''"9.

8. Gnathojjhausia elegans, G. O. Sars (PI. VI. figs. 1-5).

Gnathophausia elegans, G. 0. Sais, Preliminary Notices on the Challenger Schizopoda, No. 8.

Specific Characters. — Form of body very slender. Carapace not completely covering
the last segment of the trunk, and wanting the upper lateral keel ; the cardio-branchial sulcus
distinctly marked. Dorsal spine of moderate length, reaching to the end of the second
caudal segment. Rostrum rather elongate, equalling the carapace in length, and distinctly
denticulate throughout. Supra-orbital spines well marked, though not very strong;
antennal spines exceedingly small; branchiostegal spines wanting. Caudal segments
rather slender, not keeled above ; epimera small, with the posterior lappet but slightly
projecting. Antennal scale with the spine of the outer corner smooth, and projecting a
trifle beyond the terminal lobe. Telson linguiform, the apical spines very short, and
.separated by a denticulated cleft. Length, 56 mm.

Remarks. — This is a very fine and elegant species, somewhat resembling Gnatho-

REPORT ON THE SCiriZOPODA. 43

phausia zoea in its general form, but distiugulslicd l)otli from that and all the other
species by tho absolute want nf tlie upper latiTal ki>el, and by the distinctly impressed
cardio- branchial sulcus.

Description. — Of this species, too, a solitary specimen only was obtained, a female,
with distinct though not yet fully developed incubatory lamellae. Length of the
specimen only 56 mm.

The form of the body (see figs. 1, 2) is more slender than in any of the other species,
excepting perhaps Gnathophausia gracilis, Suhm.

As in the preceding species, the carapace does not cover completely the last segment
of the trunk, part of which may be seen exposed behind its posterior margin. It juts
out posteriorly as a comparatively strong dorsal spine, which, however, does not project
beyond the second caudal segment. Of the lateral keels the lower only is distinctly
developed, and this curves obliquely upward in its posterior part, terminating at some
distance beneath the base of the dorsal spine. The upper lateral keel, on the other hand,
distinct in all the other species of the genus, would seem in this one to be wholly
wanting. Only when viewed from the dorsal aspect (fig. 2) can two faint lines be
disc-erned, close to the dorsal keel, which, perhaps, may be regarded as corresponding to
these keels, but, if so, they have a most anomalous position. The rostrum is rather
elongate, attaining the length of the whole carapace, and is coarsely denticulate, the
denticles being continued along the upper crest to the base itself, becoming here verj'
small and crowded together. The supra-orbital spines are distinctly developed and
somewhat upturned. On the other hand, the antennal spines are exceedingly small;
and of the branchiostegal spines no trace whatever can be discerned, the lateral
expansions of the carapace behind the antennal spines being evenly rounded, as in
Gnathophausia ivillemoesii.

The caudal segments are rather slender, and, as in Gnathophausia affinis, without
any keel or dorsal projections. The epimera are very small, the posterior lappet scarcely
projecting beyond the ventral face. The last segment is conspicuously longer than the
preceding, and its two sections very distinctly marked off.

The eyes, as in the two preceding species, are quite short, and clavate in form.

The antennal scale (fig. 3) is more than double the length of the auteunular peduncle,
and of a form rather similar to that in Gnathophausia affinis, with this difference, however,
that the terminal lobe is much less produced, the spine of the outer corner projecting
considerably beyond it. This spine, too, contrary to what is the case in the following
species, is quite smooth.

The telson (fig. 4) exhibits tlie usual linguiform shape, the lateral margins being
rather strongly curved in their distal part, and densely spinulose. The apical spines are
somewhat short and thick, armed at the outer edge with a small tooth, and separated in
the middle by a distinctly angular cleft, fringed with small denticles (see fig. .5).

44 THE VOYAGE OF H.M.S. CH ALLEN GEE.

Habitat. — The ahove described specimen was taken in the Pacific Ocean, south of the
Fiji Ishinds.

Station 174u, August 3, 1874; kt. 19° 7' 50" S., long. 178' 19' 35" K; depth.
tilO fathoms; coral mud; bottom temperature, 39°"0.

9. Gnathophansia zoea, Willemoes-Suhm (PI. VI. figs. 6-10).

Gnathophmisia zocn, Suhm, Trans. Linn. Soc. Lond. (Zool.), .ser. 2, vol. i. p. .32, pi. ix. figs. 2-15,

pi. X. fig. 4, 1875.
Gnathophauxia zoea, G. 0. Sars, Preliminary Xotices on the Challenger Schizopoda, No. 9.
Gnathoj}hmisia zoea, A. Jlilne-Edwards, Receuil de Figures de Crustaces nouveaux ou peu

connus, V livraison (two last plates), Paris, April, 1883.

Specific Characters. — The body not so .slender as in the two last species.
Carapace rather large, completely covering whole of trunk, and produced behind as a
very large dorsal spine, in some specimens jutting out even beyond the fourth caudal
segment. Posterior margin of carapace in upper part coarsely denticulate, the denticles
continued along the lateral edge of the dorsal spine. Both lateral keels distinct.
Rostrum very elongate, even exceeding the carapace in length, and strongly denticulate
throughout. Supra-orbital and antenna! spines well marked and considerably projecting ;
brauchiostegal spines wanting. Caudal segments slightly keeled above, and produced
posteriorly into small spines; posterior lappet of epimera acutely pointed. Antenntd
scale with spine of outer corner somewhat projecting beyond the terminal lobe, and
slightly denticulate at the outer edge. Telson of the usual form, the apical spines
connected by a thin serrate lamella. Length reaching 70 mm.

Remarks. — This form has been well described and figured by the late Dr. v. Willemoes-
Suhm in the above cited treatise, and several figures of the same species have also been
prepared by Professor A. Milne-Edwards on two plates, belonging to a collection of drawings
of Crustacea, recently published by that author. It may readily be distinguished from
the preceding species by the very strong development of the dorsal spine, from which
character, indeed, the specific denomination ''zoea" has been derived, this name, as
is well known, being generally applied to a larval stage of Brachyura, prominently
distinguished by the presence of a large dorsal spine issuing from the dorsal surface of
the carapace.

Description. — No less than five specimens of this striking form were procured on the
Challenger Expedition from difi"erent localities. Of these, two are females and three
males, aU agreeing very closely in all essential characters. The largest of the speci-
mens, a male, attains a length of about 70 mm.

The form of the body (see figs. 6, 7) is somewhat more robust than in the three
preceding species, the anterior division being rather more dilated, and the tail not so
slender.

REPORT ON THE SCHIZOPODA. 45

The carapace is very large, covering the whole of the trunk, and even somewhat
overlapping the anterior part of the first caudal segment. It juts out posteriorly into a
remarkably strong dorsal spine of somewhat varying length, but in some specimens
])rojects, when the tail is extended, even beyond its fourth segment. This spine, too, is
rather broad at the base, and gradually tapers toward the apex, which is sharply
pointed. Both lateral keels of the carapace are distinctly marked, the lower one being
placed rather fir down, and, as in Gnathophausia willemoesii, curving abruptly upward
at a short distance from thi> infero-posterior corners of the carapace, running parallel to the
posterior margin, and joining the upper lateral keel at the base of the dorsal spine. Ihe
upper part of the posterior margin of the carapace is araied with strong denticles,
resembling the teeth of a saw, and these are continued for some distance along tlie
lateral edges of the dorsal spine. The dorsal keel is quite uninterrupted, running along
the whole dorsal surface of the carapace, and continued anteriorly on the rostrum,
posteriorly on the dorsal spine. The rostrum attains a very considerable size, even
exceeding in length the whole carapace, if the dorsal spine be excepted, and is distinctly
denticulate throughout. The supra-orbital spines (fig. 8, a) are strongly developed,
and project far beyond the eyes. The antennal spines {h) also attain a comparatively-
considerable length. On the other hand, the branchiostegal spines are wholly wanting,
the lateral expansions of the carapace (c) being evenly rounded off", as in Gnathophmtsia
willemoesii and Gnathophausia elegnns.

The five anterior caudal segments are slightlv keeled above, and, at the posterior
margin, produced as short posteriorly directed spines. The epimera project rather
more than in the two species last described, their posterior lappet being acutely
pointed.

The eyes, as in the other species belonging to this section, arc rather short, and
pyriform in shape.

The antennal scale (fig. 9) has much the same form as in Gnathophausia elegana,
fliftering only in the spine of the outer corner being slightly serrate along the
outer edge.

The telson (see fig. 10) also exhibits a very similar appearance to that in the
preceding species, but the apical spines are here connected by a thin but distinct lamella,
regularly serrate on its free edge.

The uropoda (ibid.) do not quite reach the apex of the telson, and are, in other
respects, very similar in structure to those of the other .species belonging to this section.

Colour. — According to the statements of Dr. v. Willemoes-Suhm, the Rev. Dr. Nomian.
Professor A. Milne-Edwards, and the Marquis ile Folin, the colour of this form is a
magnificent lilood-red or carmine.

Habitat. — The specimens procured l>y i\w Challenger Expedition were collected at
the following localities : —

46 THE VOYAGE OF H.M.S. CHALLENGER.

Station 73, June, 30, 1873; lat. 38' 30' N., long. 31° 14' VV. (North Atlantic, west
of the Azores) ; depth, 1000 fiithoms ; Pteropod ooze; bottom temperature, 39°'4.

Station lOG, August 25, 1873 ; lat. 1° 47' N., long. 24° 26' W. (Tropical Atlantic) ;
depth, 1850 fathoms; Globigerina ooze ; bottom temperature, 36°-6.

Station 126, September 12, 1873; lat. 10° 40' 8., long. 36° 8' W. (off Rio Sau
Francisco, Brazil) ; depth, 770 fatlioms ; red mud.

Station 171, July 15, 1874; lat. 28° 33' S., long. 177° 50' W. (Pacific, north of the
KeiTuadec Islands) ; depth, 600 fathoms ; hard ground ; bottom temperature, 39°'5.

Distribution. — As may be inferred from the above specified localities, the geographical
distribution of the present species is very extensive, ranging from the North Atlantic to
the Pacific Ocean. The species also inhabits, as stated above, the seas of Europe, having
been found by the French expedition in the Bay of Biscay.

10. Gnathophausia longixpina, G. 0. Sars (PL VII. figs. 1-5 ; PI. VIIL).

Gnathopliausia longispina, G. O. Sars, Preliminary Notices on the Challenger Schizopoda,
No. 10.

Specific Characters. — Form of body closely approximating to that of Gnathop>hausia
zoea. Dorsal spine very large, finely serrate, both at the dorsal and lateral edges.
Eostrum exceedingly elongate and slender, almost twice the length of the carapace, and
coarsely denticulate. Supra-orbital spines strongly developed ; antennal spines obsolete ;
branchiostegal spines well marked, triangular, and projecting straight outward. Five
anterior caudal segments slightly keeled above, and produced at the middle of the
posterior margin into smaU dorsal denticles ; posterior lappet of epimera acuminate, that
on the second segment remarkably produced. Anterior section of last segment with
two epimeral spines on either side. Eyes short, claviform. Antennal scale remarkably
large, with terminal lobe very narrow, the spine of the outer corner exceedingly strong,
mucroniform, and greatly surpassing the terminal lobe, coarsely denticulate on both
edges, the denticles being continued along the outer margin of the scale almost to its
base. Telson and uropoda almost the same as in Gnathophausia zoea. Length reaching
59 mm.

Remarks. — This species, at the first glance, much resembles Gnathophausia zoea
in appearance, but may readily be distinguished from it by the still more elongate
rostrum, the closely denticulate dorsal spine, the absolute want of antennal spines,
the branchiostegal projections being very distinctly marked ; and, finally, by the strong
development of the antennal scale, and more particularly of the spine issuing from its
outer corner.

Description. — Of this species also, no less than five specimens were collected, all
in the same locality. One is a female, the remainder being males. The largest

REPORT ON THE SCHIZOPODA. 47

specimen, a male, reaches a length of 59 mm. I have selected a male for anatomical
dissection, and have figured the limbs, gills, and the nervous system separately
on PI. VIII., ]io])ing in tliis way to illustrate more closely the organisation of the
genus.

The form of the body (sec PL YIl. figs. 1, 2), although rather similar to that in
Gnathophausia zoea, would appear on the whole to be somewhat more slender, the
anterior division being less tumid.

The carapace, as in that species, covers the whole of the trunk, without, however,
overlapping the anterior part of the first caudal segment. The dorsal spine is strongly
developed, projecting, when the tail is extended, to about the end of its fourth segment.
It is rlosely denticulate throughout, the denticles being present not only, as in Gnatho-
phausia zoea, along the lateral, but also on the dorsal edges, and continued forward,
moreover, along the dorsal keel of the carapace almost to the verge of the dorsal area.
The lateral keels of the carapace are comparatively shorter than in Gnathophausia
zoea, but, in other respects, exhibit a j^erfectly similar appearance. The rostrum is
exceedingly elongate and slender, even attaining twice the length of the carapace, and
it is perfectly straight, acuminate, and coarsely denticulate throughout. The supra-
orbital spines (fig. 5, a), as in Gnathophausia zoea, are strongly developed, pro-
jecting fiir beyond the eyes. On the other hand, the antennal spines would seem to
be wholly wanting, only a very small rounded prominence {h) being observed in their
place. The lateral expansions of the carapace, too, project into a strong, acutely
triangular lappet, pointing straight outward, and apparently corresponding to the
branch iostegal spines.

The five anterior caudal segments are, as in Gnathophausia zoea, slightly keeled
above, and exhibit in the middle of the posterior margin a small dorsal projection
pointing backward. The epimera project distinctly, the posterior lappet being drawn out
into a sharp point, which, on the second segment, is remarkably long and slender. The
epimeral plates issuing from the anterior section of the last segment exhibit two small
denticles succeeding each other. The terminal spines, placed on each side of the base of
the telson, are unusually strong and somewhat upturned.

The eyes, as in Gnathophausia zoea, are rather short and clavate in form.

The antennal scale (PI. VII. fig. 3), on the other hand, exhibits a rather char-
acteristic appearance. It is very large, and tapers rapidly toward the apex, the
terminal lobe being very much narrowed and lanceolate in form. The spine, too, issuing
from the outer corner, is enormously developed, decidedly mucroniform, and projects far
beyond the tip of the scale; it is also coarsely denticulate on both edges, the denticles,
moreover, being continued backward along the outer margin of the scale, almost to
its base.

The telson (fig. 4) does not diff"er materially from that of Gnathophausia zoea, nor do

48 THE VOYAGE OF H.M.S. CHALLENGED.

the several other parts show auy essential difference from what is observed in that
species.

Habitat. — All the specimens of this species were collected in the same locality, viz., off
Samboangan, Mindanao (Pliilippine Islands).

Station 200, October 23, 1874; hit. 6° 47' N. ; long. 122° 28' E.; depth, 250 fathoms;
green mud.

Section 3. — Infero-jjosterior corners of carapace produced into two spines. Dorsal spine
distinctly projecting. Dorsal keel interrupted anteriorly. Supra-orbital spines small.
Antennal scale jointed at apex, outer edge jutting out anteriorly into a strong spine.
Maxillipeds with distinctly developed exopodites. Epimeral plates of last segment not
united on the ventral face.

11. Gnathophausia gracilis, Willemoes-Suhm (PL VII. figs. G-10).

Gnathophausia gracilis, Siibm, Trans. Linn. Soc. Lond. (Zool.), ser. '2. vo). i. p. 33, pi. ix.

fig. 1, 1875.
Gnatliojiltausia gracilis, G. C>. Sars, Preliuiinary Notices on the Challenger Schizopoda, No. 11.

Specific Characters. — Form of body very slender. Carapace not very large ; dorsal
spine short, but distinctly projecting; iufero-posterior corners armed with two unequal
spines, the upper one being the stronger, and about equalling in length the dorsal spine.
Upper lateral keel wanting. Dorsal keel armed in its posterior part with coarse,
anteriorly curved denticles. Cervical sulcus distinctly defined. Eostrum elongate and
.slender, equalling the carapace in length, and distinctly denticulate. Supra-orbital
spines very small, and not defined from the base of the rostrum. Antennal spines well-
marked ; branchiostegal projections exceedingly large, acutely triangular. The two
anterior caudal segments with strong dorsal projections ; epimera small. Eyes very narrow,
cornea scarcely at all expanded. Antennal scale rather slender, terminal lobe .small, outer
edge serrate in the distal part, spine of outer corner slightly projecting. Telson lingui-
form, apical projection quadridentate, having besides a small lateral denticle. Length,
41 mm.

Remarks. — This is a rather anomalous species, perhaps most nearly related to
the species comprised in the first section, although the antennal scale is developed in
the same manner as in the species belonging to the second section. After all it
cannot be referred to either of these two sections, but should more properly be regarded
as the t}'pe of a third section, or subgenus.

Description. — The sole specimen obtained by the Challenger Expedition, nnd briefly
described by the late Dr. v. Willemoes-Suhm, does not appear to have been very carefully
handled, being in far from a good state of preservation, the carapace having been partly
crushed and disengaged from the body. It has therefore been somewhat difficult for me

llliPOltT ON THE SL'IlIZurODA. 4J>

to work]]out the sjjecifii; character.^ satisfactorily, as also to give correct figures of tlie
general appearance and form of the body. The specimen has not a trac^e of incubatory
lamelLie, and hence is most likely a male. Its length is only 41 mm.

The form of the body (figs. 6, 7), as compared with the other species of the genus,
is very slender, for which reason the late Dr. v. Willemoes-Suhm suggested the specific
<lenomination "gracilis."

The carapace is comparatively small, and does not seem to cover completely the last
segment of the trunk, it projects ^posteriorly into a well marked, although rather short,
dorsal spine, scarcely reaching beyond the first caudal segment. The infero-})osterioi-
corners of the carapace, instead of being rounded off", as in the species belonging to the
second section, are somewhat prominent, and jut out into two posteriorly directed spines,
of somewhat unequal length, the lower rather short, whereas the upper attains about the
length of the dorsal spine. Of the lateral keels, the lower only is distinctly developed,
and it runs parallel to the inferior margin of the carapace, terminating at the base of the
upper spine, which issues from the infero-posterior corner. Of the upper lateral keels, on
the other hand, no trace whatever can l)e discerned. The dorsal keel is interrupted in
the anterior part of the carapace, where a distinct transverse impression is seen to occur,
apparently corresponding to the cervical sulcus in other Schizopoda. In the posterior
part, however, the keel is well marked, and armed witli a row of strong, anteriorly
curving denticles. The rostrum is i-ather elongate and slender, about as long as the
carapace, and, as in the other species, three-edged, being also armed with strong denticles,
continued along the dorsal edge to some distance posterior to the base of the rostrum.
The supra-orbital spines are very small, and not distinctly defined from the base of the
rostrum, being placed somewhat anterior to the insertion of the eyes. The antennal
spines are well marked, though not very large. On the other hand, the branchiostegai
spines are enormously developed, and project on either side as strong wing-like expansions,
tapering to a sharp point.

The caudal segments are rather slender, and the five anterior ones are armed with
dorsal projections, those on the two foremost being distinguished by their exceedingly
large size. On the second segment occur two such projections, of an acutely triangular
form, both placed in the middle line, and pointing the one posteriorly, the other anteriorly.
On tlie first segment may also be observed two projections, of which, however, the
anterior is very small, whereas the posterior is rather large, and points straight upwaril.
On the other segments, only a small projection is seen in the middle of the posterioi-
margin. The epimeral plates issuing from the anterior section of the last segment are, as
in Gnat}tx)phausia longispina, armed with two small denticles.

The eyes are very small and narrow, the cornea being scarcely expanded, and only
occupjdng the outermost extremity of the eye.

The antennulae do not seem to exhiliit any essential difference from those in other

(ZOOL. C'HALL. EXl". PAUT XXX VII. — 1 88-5.) < 'O 7

50 THE VOYAGE OF H.M.S. CHALLENGER.

species of the geuus, except, perhaps, that the inner fiagellum is comparatively smaller,
not nearly reaching the length of the antennal flagellnni.

The antennal .scale (fig. 8) is about twice as long a.s the antennular peduncle and
rather nai-row, almost three times as long as broad, but in other respect.s exhibiting a
structure similar to that observed in the species belonging to the second section of the genus,
the terminal part being marked uti' from the remaining portion of tlie scale by a distinct
oblique .suture, and jutting out into a .short linguiform lobe. The inner edge of the scale
is very slightly arched, and, like the terminal lobe, fringed by a row of comparatively
strong bristles. The outer edge, too, is almost straight, and in its distal half slightly
serrate, projecting anteriorly into a naked spine of moderate length.

With regard to the oral parts, they cannot of course be accurately examined in the
solitary specimen obtained, Ijut would seem on the whole to agree with those in Gnatho-
phattsia longispina, as descril)ed al)0ve; with this diflerence, however, that the maxillipeds.
as in the three species belonging to the first section, have distinctly developed exopodites.

The legs and caudal limbs do not exhibit any essential difi'erence from the same parts
in the other species of the genus.

The telson (see fig. 9) exhibits the usual linguiform shape, and its length about equals
that of the two preceding segments taken together. Its lateral edges are evenly curved in
their distal part, and densely spinulose. The apical projection exhibits a form somewhat
dijferent from that in the other species (see fig. 10), being drawn out into four acute
terminal lappets, or spines, the two outer ones being the largest and smooth, whereas the
two inner ones are denticulate along the inner edge, and separated by an angular cleft.
Moreover, a short denticle is observed on either side at the outer edge of the
projection.

The uropoda {ibid.) do not quite reach the tip of the telson, and they exhibit the
usual structure, the outer plate being the larger, and having the terminal part marked
off as a distinct joint, jutting out in the form of a rather large linguiform lobe, densely
fringed with bristles. The outer edge of this plate is considerably less arched than in
the other spe(;ies, and terminates in a very small denticle.

Habitat. — The specimen described above, together with Gnathophausia affinis, was
taken in the tropical part of the Atlantic Ocean between Africa and Brazil.

Station 107, August 26, 1873 ; lat. 1° 22' N., long. 26° 36' W. ; depth, 1500 fathoms :
Globigerina ooze ; bottom temperature, 37°'9.

Genus 4. Chalarnspis, Willemoes-Suhm (ex parte).

Generic Characters. — Carapace thin, membranous, of enormous size, covering, in
addition to the trunk, the anterior part of the tail, and projecting forwards as a broad
troutal plate. Caudal segments with rounded epimera. Eves small. Antennular

REPORT ON THE SUHIZOPODA, 51

peduncle short and thick, inner flagellum very small. Antennal scale not jointed, outer
edge serrate. The two (?) anterior pairs of legs ditier slightly from the rest, which
are uniform in structure, and true perciopoda. Telsnu prolouged, acuminate. Outer
plate of uropoda not jointed at apex.

Remarks. — The specimen from which the ])reseut genus is estal)lished has
unfortunately been lost. But to judge from the drawings of tlic animal made by the late
Dr. V. Willemoes-Suhm, it certainly claims to be regarded as the type of a distinct
o-enus amonof the Lophogastridge. The generic name Chalarasjv's has, it is true, been
also adopted by that author for another very diflerent ^chizoTpod^Chalara.spts
tinguictdata ; l)ut as that form has proved to be identical with Dana's Eiicopia audraiis,
I have thought fit to retain the generic denomination ]iroposed by Dr. v. WiUemoes-
Suhm for the remarkable form here treated of, tlic name being, moreover. ,i most appro-
priate one.

12. Chalaraspis cdata, Willemoes-Suhm MS. (Woodcuts 1. 2).

Specific Characters. — Form of body rather short and thickset. Carapa(!e without
either keels or sculpturing, emarginate behind, wholly covering the two anterior segments
of the tail, as also a part of the third segment. Cervical sulcus distinct. Frontal plate
abruptly truncate, anterior margin finely serrate. Eyes very small and narrow. Auten-
uular peduncle projecting with its two outer joints beyond the frontal plate. Antennal
scale not very large, of an oval form, apex rounded. Telson, equalling in length the three

Fig. \. —Chalaraspis alatn, Sulim.

j)receding segments taken together, rather narrow, and tapering towards the apex.
Length, 40 mm.

Remarks. — As above stated, the only specimen obtained by the Challenger Expedition
has been lost, and hence T have not myself been enabled to submit the species to a
detailed examination. However, the two drawings of this interesting form were for-
tunately found among the manusci-ipts of the late Dr. v. Willemoes-Suhm, — the ou<>

iy-Z

THE .VOYAGE OF H.M.f-'. CHALLENGE!!.

N ■-. i

cxliibiting the animal from the right side, the other as seen from above. The accom-
[lanving woodcuts have been executed with the greatest possible accuracy from these

drawings, and in the following description are also embodied
certain manuscript notes l^y the same author.

Description. — The specimen has, according to the late Dr.
V. Willemoes-Suhm, a length of 40 mm., of which the caraj^ace,
measured along the upj^er face, occupies 20 mm.

The form of the 1>ody, as will be seen from the figures, is
comparatively short and thickset, even more so than in the
species of the genus Gnathophausia.

The carapace is enormously developed, covering not only
the whole of the trunk, but also a very considerable part of
the tail, of which the two anterior segments are comj)letely
concealed beneath it. It is very thin, membranous, and semi-
transparent, and does nut exhibit any trace of keels or other
sculpturing, nor jut out distinctly into spines. Throughout
by for the greater part L>f its extent, it loosely covers the
body like a mantle, being connate with it in its most anterior
part only. Posteriorly, it is deeply emarginate, the lateral
parts forming broadly rounded and very deep wng-like
expansions, overlapping the third caudal segment, and more
or less completely concealing at the sides the three an-
terior pairs of caudal limbs, as also the basal parts of the
legs. Anteriorly, it projects as a short, but very broail, frontal plate, abruptly
truncate at the extremity, the anterior margin Ijeing slightly emarginate and finely
serrate, the lateral corners somewhat extended. At a short distance behind the
frontal plate a distinctly marked transverse suture occurs, apparently corresponding
to the cervical sulciis in other Schizopods. The antero-lateral corners of the carapace
form an acute angle. No supra-orbital, antennal, nor branchiostegal spines can be
detected.

The caudal segments appear somewhat compressed, and exhibit a slight transverse
impression close to the posterior margin. The epimera are evenly rounded, as in
Lophogaster. The last segment would not seem to lie subdivided transversely, and it
has a small epimeral spine on either side.

The eyes are very small and narrow, with the cornea but slightly expanded ; they
[troject a little on either side of the frontal plate.

The antennular peduncle is short and thick, the basal joint being wholly concealed
liencath the frontal plate, whereas the two outer joints project beyond its anterior margin.
.Vs in Giuithophaitsia, the last joint juts out on the inner side as a densely setigerous

Fin. 2. — Chobiru.'tpis alata, Suhm.

HKPUltT UN THE SCH IZDFODA. 53

]()l)e, i)ointing forward. (_)f tlif Hagella, the iniici- oiu- Wduld scciii to I)e very small,
wliereas the outer is strongh^ developed.

The antenna! scale is cdnniarativelv small, and has nn articulation at the extremity.
It is oval in form, the apex being rounded off. and the outer edge distinctly
serrate.

Of the legs, tlie two anterior pairs, judging from the figures, would appear to differ
somewhat from the rest, their terminal ])art l)eing a little stronger and more curved.
The remaining legs are uniform in structure and not veiy strong, hut hav(> a distinct
terminal claw.

The incubatory lamella? (Kig. 1, ce) were well marked in the s[)ecimen examined, and
were present, as in the other forms of this iamily, at the ba.ses of all the legs.

The caudal limbs would not seem to differ in structure from those of other Lopho-
gastridai.

The telson is greatly jjroduced, and very narrow, tapering gradually towards the
a})ex, which is acutely pointed ; the lateral edges are almost straight, and in one of the
figures ajspear finely serrate.

The uropoda are rather large, reaching the tip of the telson, and have lioth plates
lanceolate, the outer one being somewhat broader, without, however, exhibiting any articu-
lation at the apex.

Habitat. — The aljove described specimen was taken in the Southern Ocean, south of
Australia.

Station 158, March 7, 1874; lat. 50° l' S., long. 123' 4' E.; deiith. 1800 fathoms;
(41obigerina ooze; bottom temperature, 33''5.

Family II. EucopiiD,^.

liejiiark/^. — This family, so far as at present known, contains but a solUar\' t\pe, viz., the
genus Eucopia, established by Dana for a remarkable Crustacean obtained by the United
States Exploring Expedition, and named l)y that author Eucopia aunindi:^. This form
was classed l)y Dana within his division Penseidea, and Mr. Spence Bate has recently '
adopted the same view in regard to the systematic jjosition of the genus. ( )n the other
haml, the late Dr. v. Willemoes-Suhm, who rediscovered the same .species during the
( 'hallenger Expeclition, regarded it as the tjV^ ^f a new family of the Schizopoda. But,
having apparently not consulted Dana's work, he described the animal as a new form under
the name of Chalaraspis iinguiculata, and accordingly named the family Chalarasjtidje.
In my opinion, the view of Dr. v. Willemoes-Suhm, as to the systematic [losition _^of
the present form, is undoubtedly quite correct. The eailier name, however. Eucopia,

' On till' Penmdea, Ann. and Mag. Xut. Hist., ser. rt, vol. viii. |i]i. IC!)- !!)(;, ISsl.

TA THE VOYAGE OF H.M.S. CHALLENGER.

proposed liy Dana, must be retaineil. .md tlio family hereafter named Eucopiidaj, iu
liou of Chalaras]ii(l8e.

The sfhizopodous nature of Eucopia is apparent both iu the powerfully developed
natatory branches (exopods) of all the legs, and more particularlj^ in the marsupial poueh
of the female, the latter exhibiting 25recisely the same structure as the same part in the
Lophogastridse. Indeed this last character alone would suffice to distinguish the species as
a true Schizopod, no other Podojjhtlialmians possessing, as stated above, a similar character-
istic. Moreover, the structure of the oral parts would seem to bear out this assumption,
for thev are. on the whole, rather similar to those in other true Schizopods. Thirdly,
the structure and arrangement of the gills exhibit a striking resemblance to those of the
corresponding parts in the Lophogastridfe. On the other hand, however, the very
peculiar and anomalous form of the legs would apparently prevent us from ranging
this Crustacean wdthin any of the three jireviously established families of Schizopoda, and
for this reason I have seen fit to adopt the view of the late Dr. v. Willemoes-Suhm in
regarding it as the type of a separate family.

Genus Eucopia, Dana, 1852.

Eiicopia, Dana, United States Exploring Expedition, Crustacea, part i. p. (iOO.
Chalarnspis, Sulim (ex parte).

Generic Characters. — Integuments very thin and soft, membranous, t'arapace large,
<-overing whole of trunk, deeply emarginate posteriorly, lateral wings produced along the
.sides of tail ; frontal part rounded off, not rostrate. Caudal segments without distinct
epimera, smooth. Eyes imperfectlj^ developed. Antennular peduncle rather stout, inner
flagellum very small, outer strongly developed. Antennal scale large, jointed at apex.
Mandibular palp very slender. Maxill?e rather feeble iu structure ; first pair without
any palp, second pair with very small masticatory lobes, provided with only simple
l)ristles. Maxillipeds furnished with an imjaerfectly developed exopodite, the epipodite
exceedingly large. The three anterior pairs of legs short and strong, developed as
gnathopoda ; the three succeeding pairs exceedingly slender and elongate, mth propodal
joint slightly expanded and terminal claw very mobile : last pair filiform, outer part setose.
Branchife well developed, consisting of three bipiunate ramifications, the inner one
projecting beneatb the ventral face, the two others covered by the carapace. Pinnulse of
gills irregularly lobular. No branchiae at base of last pair of legs. Marsupial pouch
composed of seven pairs of incubatory lamellae. Telson rather large, tapering ; apex
entire, not incised. Outer plates of uropoda jointed at apex.

Remarks.- — The genus does not. in my opinion, at present comprise more than a
.single species, described in detail below. Mr. Spence Bate having examined some of the
specimens from the Challenger Expedition, does indeed suggest that one of these is

KEPORT ON THE SCHTZOPODA. 65

the representative of a new species, to which he assigns the name oi Eucopia equatona,
but after a careful examination of this, I feel convinced that it ought to he regarded
US ii male of EKCojna av.strali,s, the assumed specific differences being readily accounted
for as mere sexu;ii characters.

13. Eucopia (distrdlis, Dana (Pis. IX. and X.).

Eucopia aiisfralis, Dana, Uuittil States Exploring Expedition, Crustacea, part i. p. 609 ; Atlas,

pi. xi. lig. 10, a tu m.
Ckalaraspis mu/uiculafa, Sulim, Trans. Liuu. Soc. Loml. (Zool.), ser. 2, vol. i. p. 37, pi. viii., 187.5.
I'Jucopia amtruUt!, G. 0. Sars, Preliminary Notices on flic Challenger Schizopoda, Xo. 12.

Specific Characters. — Form of body rather slender, tail tapering backward very
considerably, with last segment very elongate. Carapace indistinctly areolate in its
anterior part, cervical and Ijranchiostegal lines well marked ; lateral wugs rounded off
at the tip and projecting far beyond the first caudal segment. Frontal margin evenly
arched. A slight infra-orbital projection present, but no trace of supra-orbital, antennal.
or branchiostegal spines. Eye small, cornea scai"cely expanded at all ; in male some-
what larger, with darker pigment. Last joint of antennular peduncle produced interiorly
into a setiferous lobe. Antennal scale oblong-ovate, apex rounded, outer edge some-
what sinuous, and terminating in a very small denticle. The three anterior pairs of
gnathopodous legs in male rather stronger than in female, the propodal joint being greatlv
swollen ; the three succeeding pairs of legs attaining almost the length of the whole body,
propodal joint slightly dilated and strongly spinous at the distal part of its inner edge,
terminal claw scarcely half as long, straight and spinous at base. Terminal part of telson
fringed with unequal spinides, the apex being armed with two straight spines, between
which two small bristles are attached. Uropoda attaining length of telson, outer plate
•obliquely truncate at apex, with three small denticles at the end of the straight outer
edge. Length reaching 50 mm.

lic'inarks. — There cannot, I think, be any doubt whatever that this form is
identical with Dana's Eucopia australis. The author in question, it is true, does
not describe the very peculiar structure of the three pairs of legs preceding the last, but
merely remarks that the four posterior pairs are very long and slender, from which it
might be inferred that all these pairs have had a uniform appearance in Dana's specimen.
It must, however, be borne in mind that the solitary example described by Dana was not
in a very good state of preservation, having been taken from the stomach of a penguin,
and Dana, moreover, states, that the four posterior jJidrs of legs were partly broken.
In all other respects the figures and description of Dana agree sufficiently well with tlie
form here treated of, and described by the late Dr. v. Willemoes-Suhm under the name
of Chalaraspis tiiunncalaUi.

56 TIIK \OYA(iK OF H.M.S. (;HALLENGErv.

iVlthough the present species would seem to l)e widely distiilmted, and a ratliei-
plentiful .sujiply of specimens was colleftcd by the Challenger Expedition, it has
proved a matter of no small difficulty to make out its anatomy and to arrive at a correct
idea of the general appearance of the animal, most of the specimens, owing to their great
fraoilitv, beino- in a ratliei' imperfect state of preservation, and having lost a more or less
considerable numl>cr of their limbs. Plowever, by comparing all the specimens, and
supplying from one what is wanting in another, I have finally succeeded in attaining
a tolerably complete knowledge of the organisation of this remarkable Crustacean, and at
the same time have l)een enabled to confirm the statements of the late Dr. v. Willemoes-
Suhm, as to certain important characteristics omitted in the description given by Dana.

Description. — The length of the largest specimen, a female with remarkably
developed marsupial ])0uch, is 50 mm.

All the integuments are very thin and soft, almost membranous, and hence the
o-eneral form of the bodv has in most cases been somewhat altered bv the action of the
spirit or by accidental pressure.

In the best preserved specimens, the body exhibits (see PI. IX. figs. 1,2; PI. X.
fig. l) a rather slender form, the anterior division lieing almost cylindrical, the posterior
tapering rapidly towards the end.

The carapace is very large, and, as in Gnathbphausia, connate with the body in its

most anterior part only, but otherwise loosely covering the trunk, all the segments of

which are distinct!)' defined in their whole circumference (see PL X. fig. 2), the last

being perceptibly larger than the others. It is deeply emarginate posteriorly, mthout,

however, as stated by Dana, leaving any of the segments of the trunk uncovered. The

lateral wings are rather jiroduced, and rounded at the tip, extending laterally along the

anterior part of the tail and reaching far bej^ond its first segment, in some specimens

almost to the end of the second (see PL IX. fig. l). The inferior margins, too, are very

slightly arcuate, covering in part the bases of the legs, and terminating anteriorly in

an obtuse angle. The anterior part of the carapace exhibits above an indistinctly

areolate appearance, two transverse depressions, one of which may l)e the cervical

sulcus occurring here, partly crossed by a slight longitudinal depression on either side.

Moreover, the l)rauchiostegal line, marking off the linguiform dorsal area, is distinctl\-

perceptil)lc (see PL IX. figs. 1. 2). The frontal margin is evenly curved, not

forming any rostral jirojection, and leaving the ocular segment uncovered. Beneath

and somewhat external to the eyes, on either side, a slight projection is seen, apparently

corresponding to the infra-orbital spine in other Podophthalmians. On the other hand.

no trace whatever c;in be found of either supra-orbital or of nutcnnal and In'anchiostegal

spines.

The caudal segments do not exhibit any distinctly developed epimera, being evenly
rounded both ventrally and dorsally. They rapidly diminish in l^readth posteriorh', and

REPORT OX THE SCHTZOPODA. 57

the last segment is very luudi compressed, as also exceedingly elongate, equalling in length
the three preceding segments taken together.

The eyes (see PL TX. fig. 3) in the female are very small, and nearly cylindrical,
with the cornea not in the least ex])anded, and are furnished with a whitish pigment.
The visual elements would also seem to be most imperfectly developed. In the male (see
PI. X. fig. 13) the eyes are rather larger and thicker, with a darker pigment, l)ut here,
too, the visual elements do not exhibit any complete development. Both in the male and
the female a distinctly marked ocular papilla is seen projecting anteriorly over the upper
part of each cornea. The ocular segment projects anteriorly as a broadly rounded lobe,
reaching a trifle Ijeyond the insertion of the eyes (see PI. IX. fig. 3).

The antennular peduncle (see PI. IX. fig. 3) is rather stout, and somewhat flattened
throughout. Its basal joint is almost as large as the two other joints taken together, and
finely setiferous along the inner edge, as also partly on the upper face ; its outer edge
exhibits a few (three) somewhat stronger plumose bristles, and terminates in an almost
perfect right angle, from which proceed a Inmdle of similar Inistles. The second joint is
rather short, and connected with the last by a very oblique suture, running from ^\'ithout
inwards. The last joint has the inner edge sharjiened and projecting anteriorly as a trian-
gular lobe, with a fringe of dense and very long plumose bristles, carried along the whole
of the inner margin. The inner flagellum is very small, only slightly exceeding the
peduncle in length. The outer, on the contrary, is most powerfully developed, equalling,
it may be, the whole body in length. In none of the specimens, however, is the outer
flagellum quite complete, a more or less consideralile portion being invariably l)roken ofi".

The antennal scale (see PI. IX. fig. 4) is rather large, projecting fiir beyond the
antennular peduncle, and in form is somewhat oblong-ovate, slightly tapering toward the
apex. The outer edge is a trifle arched in its proximal part, and terminates in a very
small dentiform projection ; the inner edge is very slightl}' arcuate, and the apex forms a
broadlj^ rounded lobe, marked off from the remaining part of the scale by a distinct oblic[ue
suture, and fringed with a dense i-ow of long bristles, carried along the entire inner edge
of the scale. The flagellum is strongly developed, the basal part consisting as usual
of three joints, — the last by far the largest, — and the terminal part, according to the
statement of the late Dr. v. Willemoes-Suhm, even exceeding the whole of the body
in length.

The anterior lip (see PI. IX. fig. 5) forms a rounded triangular prominence, somewhat
narrower than the same part in Gnatho2ohausia.

The posterior lip (fig. 8) has the lateral lobes somewhat expanded and in-egularly
rounded off, their inner edges lieing finelj' ciliated.

The mandibles (see fig. 5) exhibit, in respect of their bod\', a structure very similar to
that in the Lophogastridse, the cutting edge being irregularly and coareely dentate, and
exhibiting, moreover, a small molar area posteriorly. The palp, on the other hand, is verj'

(ZOOL. CHALL. E.XP. — PART XX.KVII. — 1885.) Oo 8

58 TJIE VOYAGE OF H.M.S. CHALLENGER.

slender and elongate, almost twdce as long as the hod}^ the middle joint being much the
largest, and furnished on both edges with slender bristles. The last joint is rather small,
scarcel}? attaining one-third of the length of the middle joint, and having the distal part
of the inner edge slightly emarginate, and armed with a dense row of bi-articulate
spinules, and likewise with a series of simple bristles.

The first pair of maxillae (fig. 9) are rather small, without any trace of a palp or an
exognath. Of the two masticatory lobes, the outer is much the stronger, and is armed
at the abrujitly truncated tip with a double row of strong spines (fig. 10). The inner
lobe is exceedingly small, triangular, and furnished with a single apical seta, as also a few
very small bristles on the outer margin.

The second pair of maxillae (fig. 11) are decidedly membranous throughout, exhibiting
a structure most resembling that in Lophogaster. As in that genus, the palp is very
small, although distinctlj^ bi-articulate. The masticatory lobes are unusually short, and,
as is also the case with the outer joint of the palp, provided with but a few simple bristles.
'I'he outer lobe is slightly bifurcate at the apex. The exognath is very large, elliptical,
and fringed with a dense row of very strong, plumose setse. No projection could be
observed at the outer side of the basal part.

The maxillipeds (fig. 12) exhibit on the whole a structure very similar to that in
Lophogaster, but appear somewhat more membranous. The l)asal part is rather broad,
and filled up vdth. the strong muscles giving movement to the epipodite. The five-jointed,
incurving terminal portion, or palp, is scarcely as long as the basal part, and setose on
iioth margins. Its last joint (dact5'lus) terminates in a strong spine, and is provided,
at the inner edge, with three smaller spines, and also a few short bristles. The exopodite
is rather small, and has the form of a simple, narrow plate, fringed with plumose
setse. The epipodite, on the other hand, is enormously developed, lanceolate in form,
and of a very soft and almost spongy structure.

The legs, as stated above, exhibit a very peculiar structure, and are, contrary to what
is observed in other Schizopods, rather dissimilar in appearance. All, however, having
powerfully developed natatory branches, or exopods, point out their schizopodous
nature.

The three anterior pairs of legs (see PI. IX. figs. 13, 15, 17) are rather short and
powerful in structure, generally inclining toward the oral parts, and from this feature
they would seem to be endowed with the function of true gnathopoda. Tliej'' increase
somewhat in length posteriorly (see fig. 1), the anterior pair, corresponding to the
gnathopoda in other Schizopoda, being less powerfully developed and more membranous
in structure than the two remaining pairs ; they are also furnished with longer bristles.
In all of them the basal joint is somewhat produced, transversely oval, constituting witli
the remaining part of the leg a strong elbow-shaped cui-ve. The carpal joint is rather
elongate, and furnished in the two anterior pairs (figs. 13, 15), at the distal part of the

REPOllT UN THE SCHIZOPODA. 59

iuuer edge, with a, deuse i(jw of slender spiiiules, iu addition to the usual bristles. TIk;
propodal joint in the first pair (fig. 13) is quite simple, and scarcely dilated at all, forming
therefore no ]ialmar margin. In the two succeeding pairs (figs. 15, 17), however, this
joint is conspicuously dilated, and forms, at the end of the inner edge, a more or less
distinctly marked palmar margin (figs. 16, 18). The terminal joint or dactylus, in the
first pair (fig. 13), is almost straight, in the two other pairs (figs. 16, 18), on the contrary,
strongly curved, and denticulate at the inner edge, as also very mobile, admitting of
being bent in toward the palmar margin of the propodus. In the male, these two paire
of legs (see PI. X. figs. 14, 16) are much more powerful than in the female, the propodus
being exceedingly dilated and filled up with strong muscles moving the curved dactylus.

The three succeeding pairs of legs (see PI. X. figs. 1,5) are ygtj remarkable, not only
by reason of their extraordinary length and slender form, l)ut on account of their
anomalous structure. They almost e(|ual the whole body in length, if the caudal fan be
excepted, and, in the specimens j^reserved in spirit, generally exhibit a strong elbow-
shaped curve at the junction between the ischial and meral joints, the proximal section of
the legs being more or less directed backward, whereas the terminal section extends at
rio-ht aneles with it anteriorly, reaching far in advance of the fore part of the bod\'
(see PL X. fig. 1). They all exhibit a very similar structure, except that the basal
joint diminishes rapidly in length posteriorly, while the terminal section of the leg
in a corresponding degree increases in length, though more sHghtly. Hence they all
reach, when stretched out anteriorly, to about the same transverse line. Of the several
joints, the basal one is quite remarkable for its considerable length, more especialh^ in the
first of the above pairs (fig. 5). The proximal part of this joint is somewhat dilated, and
strongly curved, whereas the distal part is very slender, and, in the first of these pairs,
projects even far beyond the tip of the exopod. The ischial joint is comparatively short,
and somewhat dilated at the end, where it contains the muscles moving the terminal
section of the leg. This is exceedingly slender, and, like the remaining part, but very
sparingly beset ^dth short bristles. The meral joint is a trifle longer than the caqial, and
somewhat curved. The propodus, too, is somewhat shorter than the carpus, and slightly
dilated at the base, tapering toward the apex, and exhibiting at the distal part of the
inner edge a distinctly marked palmar margin, armed with long, slender spines. The
terminal joint, finally, forms an exceedingly movable, almost straight, claw, spinulose at
the inner half, and admitting of being lient closely in towards the palmar margin. As to
the function of these peculiarly formed legs, it is diflicult to form a definite oi)inion,
without having observed the living animal. They would not seem to lie specially adajited
for the usual ambulatory motion, but are more likely used for the purpose of seizing hold
of any delicate submarine objects, as Hydroids or Crinoids, fixed at the sea bottom.

The last pair of legs (see PI. X. fig. 2) are rather elongate, though falling con
siderably short of the length of the three preceding pairs, nor do they exhibit their

60 THE VOYAGE OF H.M.S. CHALLENGER.

very slender form. Tliey are nearly of the same thit-kness throughout, and rather
abundantly furiiislied with 1)ristles. The terminal joint has not the appearance of a claw,
hut is linear in shape, and very densely setigerous, more especially at the inner edge, the
apex being obtusely rounded.

The gills (see PL X. fig. 2) occur at the bases of all the legs, except the last, and
present alike in their arrangement and structural details a great resemblance to the
same organs in Gnathoj^hausia. They are divided into three principal l)ranches,
the largest bent in towards the ventral face (see PI. IX. fig. 14), whereas the two others
are wholly covered by the lateral parts of the carapace. Every branch is more or less
distinctly bipinnate, and the pinnulae are divided into numerous rather irregularly
disposed, lobular projections (see PI. X. fig. .3). In the interior of the lobules small
opaque granular bodies are scattered, apparently blood-cells, similar to those observed
\\ithin the several oral parts, and also to some extent mthin the legs. In the male, the
gills (see PL X. figs. 14, 16) are, on the whole, precisely similar to those in the female,
excepting that the inner branch (fig. 15) is somewhat larger and more decidedly
arborescent, the pinnulse being in part subdivided.

The marsupial pouch in one of the specimens obtained (PL IX. fig. l) is very large,
and projects considerably beneath the trunk. As in the Lophogastridse, it is composed of
seven pairs of large ovato-lanceolate lamellge, setigerous at their edges (fig. 15), and
each overlapping the other in the median line.

The caudal limbs (PL X. fig. 8), as in the Lophogastridse, are developed in both sexes
into powerful natatory organs, the terminal branches very slender and subdivided into
numerous short setigerous joints. In the male these limbs (fig. 17) are somewhat more
strongly developed than in the female, the basal part being rather more dilated, and
exteriorly jutting out into a rounded lobe. In lx)th sexes the inner branch is a trifle
shorter than the outer.

The telson (see PL X. fig. 9) is rather elongate and slender, gradually tapering in its
outer part toward the apex, which is narrowly truncate. The lateral edges of the telson
are in the distal part armed with a row of rather strong Ijut somewhat unequal spinules,
and two simdar Ijut considerably longer ones occur on the apex, in addition to two small
l)ristles in the middle.

The uropoda [ibid.) somewhat exceed the telson in length, and have the inner plate
lanceolate, the outer rather broader and obliquely truncate at the apex, or j)rojectiug as a
short terminal lolie, marked off from the plate Ijy a distinctly defined transverse suture.
The outer edge of this plate is perfectly straight and bare, terminating in an obtuse
angle, from which issue three short denticles (see fig. 11).

The caudal fan of the male agrees precisely in aU its details with that of the female.

Nervous System. — In extracting the ventral cord from the specimen selected for
anatomical examination, I failed to discover more than seven ganglia belonging to the

REPORT ON THE SCHIZOPODA. 61

anterior division of tlie Ijody (see PI. X. fig. 12), and tlioref(jre at first suppo.sed
the foremost to liavc been very possibly lost in dissection. Subsequently, however,
I learnt that Mr. Spence Bate, too, did not find a greater numl)er in the specimen
he dissected, and, moreover, that this zoologist has found the hist segment of the
trunk to want a separate ganglion, a feature likewise sliuwu lo characterise several
forms of the Penaeidea. The ganglion belonging to the penultimate segment of the
trunk, according to the statement of the same author, besides furnishing that segment
and its appendages with nerves, also sends ntf on each side a nerve tu the last pair of
legs. Hence, the total number of ventral ganglia l)elongiug to the anterior division of
the body, counting those that supply tlic oral parts with ner\^cs as one, would not
strictly be more than seven.

In regard to the structure of the gangha (see PI. X. fig. I "2) they exhibit, as in
Gnathophansia, a very similar appearance, forming rounded masses of granular nerve-
substance, connected l)y distimt fibrous commissures. Those of the anterior division
oi the body are perfectly uniform in size, and somewhat larger than the caudal
>mnolia. The commissures, too, counectino- the "ansilia of the trunk are rather
thick, and lie close together in such a manner as readily, at the first glance, to be
taken for single, while those between the caudal ganglia are distinctly sejijarated and
rather long. In addition to a strong nerve-trunk, proceeding from either side of the
ganglia and supplpng the corresponding pair of limbs with nerves, another pair of
nerves is seen to originate from The commissures themselves, apparently innervating
the muscles of the Ijody.

Colour. — According to the statement of the late Dr. v. Willemoes-.Suhm, the animal
exhibits, in a fresh state, a bright red colour throughout.

Habitat. — The specimens procured by the Challenger Expedition were collected from
the following seven localities: — ■

Station 50, May 21, 1873; lat. 42' 8' N., long. 63° 39' W. (North Atlantic, south
of Nova Scotia); depth, 1250 fathoms; blue mud; bottom temperature, 38°"0.

Station 73, June 30, 1873; lat. 38° 30' N., long. 31° 14' W. (North Atlantic, west
of the Azores) ; depth, 1000 fathoms; Pteropod ooze; bottom temperature, 39°'4.

Station 92, July 26, 1873 ; lat. 17° 54' N., long. 24° 41' W. (Tropical Atlantic, north
of the Cape Verde Islands) ; depth, 1975 fathoms ; C41obigerina ooze.

Station 107, August 26, 1873; lat. 1° 22' N., long. 26° 36' W. (Tropical Atlantic,
about midway between Africa and Brazil); depth, 1500 fathoms; Globigerina ooze;
Ijottom temperature, 37°'9.

Station 146, December 29, 1873; lat. 46° 46' S., long. 45° 31' E. (Southern
Ocean, between Cape of Good Hope and Kerguelen) ; depth, 1375 fathoms; Globigerina
ooze; bottom temperature, 35° '6.

Station 158, March 7, 1874; lat. 50° 1' S., long. 123° 4' E. (Southern Ocean.

62 THE VOYAGE OF H.M.S. CHALLENGER.

south of Australia); depth, 1800 fathoms; Globigeriua ooze; bottom temperature,

33°-5.

Station 237, Juue 17, 1875 ; kt. 34° 37' N., luug. U0° 32' E. (North Pacific,
off Kauagava, Japan); depth, 1875 fathoms; blue mud; bottom temperature,

35°-3.

It should, however, be stated that, iu all probability, this form was observed during
the course of the Expedition in many localities other than those enumerated above. But
the great fragility of the animal may in most cases have rendered the specimens, when
brouo-ht up in the dredge or trawl, so very defective as apparently to leave them worth-
less for preservation. Thus the late Dr. v. Willemoes-Suhm says, he was " almost sure
to get at least a fragment of this Crustacean whenever, iu the Mid Atlantic, true deep-sea
animals came up iu the dredge or trawl."

The specimen described by Dana was from the Antarctic Ocean, lat. 66^ 12' S., long.
149° 44' E.

As will appear from the above named localities, this Schizopod would appear, ou the
whole, to be a true deep-sea form, rauging, as it does, from a depth of 1000 to 1975
fathoms. It is worthy of remark, however, that the specimen described by Dana was
taken from the stomach of a penguin ; and, as it cannot be reasonably assumed that
any air-breathing animal can descend to the enormous depths stated above, the said form
may also be considered as occasionally occurring at a less considerable depth. It would
seem, too, that this view is in part corroborated by the statement of the late Dr.
V. Willemoes-Suhm, who says that in the Atlantic this species is met with at depths
ranging from 350 to 2500 fathoms.

Distribution. — The late Dr. v. WiEemoes-Suhm observes concerning this form that " it
is the commonest Schizopod of the deep-sea fauna, and seems to enjoy a very wide
l)athymetrical and geographical distribution." Indeed its geographical range, as
may be seen by comparing the above stated localities, is quite astounding, for it is
met with not only throughout the great depths of the Atlantic, but also in the
Antarctic Ocean, the Australian Seas, and even in the Pacific, as far north as Japan. No
less perplexing, too, would appear the bathymetrical range of the species, descending, as
it does, according to the statement of Dr. v. Willemoes-Suhm, to the enormous depth of
2500 fathoms, while, on the other hand, the fact of its forming occasionally the food of
penguins would seem to give evidence of its occurrence, in the Antarctic Ocean, at a not
vevy considerable depth below the surface of the sea.

Family 3. EuPHAUSiiDyE.

A very considerable number of forms belonging to this interesting family was
collected by the Expedition. As most of the species lead a truly pelagic existence, the very

REPORT ON THE SCHIZOPODA.

extensive use of the surface-net on the Expedition proved highly successful. In regard to
the capture of Euphausidians this may pre-eminently be said to be the case, scarcely a single
haul failing to yield some of the forms comprised in this group, either adult or larval.
I have carefull)^ gone over a vast number of surface gatherings, kindly sent me by Dr.
John Murray, and from these have selet^ted every form that belongs to the Euphausiidse.
A large proportion of the specimens thus l)rought together represent various stages of
development : and it has therefore been a matter of no slight difficulty to determine in
each case with full certainty whether the specimens should be regarded as adults, or
whether merely as younger animals. I have been equally perplexed in attempting to
refer the larval forms accurately to the several species. Meanwhile, a careful study of
numerous specimens has finally enabled me to trace the development of at least three
different forms belonging to as many genera, and I shall give a detailed account of these
researches when treating of the development of the Euphausiidse.

The total number of species represented in the collection amounts to no less than
twenty-seven, comprising seven distinct genera, of which four are new.

I give below a synopsis of the genera, worked out from the structure of the legs.

Both the two posterior pairs quite rudimentary, Euphamia, Dana.

nearl}' uniform in
structure, and simi-
lar in appearance
to the maxUlipeds.

Less

Last pair only rudi-
mentary; penulti-
mate pair

\ of sime appearance as
I preceding,

I with outer joints of
[ stem confluent,

All the legs distinctly developed,

somewhat unequally
developed, one of
the anterior pairs <
being greatly elon-
aate.

First pair of legs greatly
produced and

rather strong, the two
last jointsarnied with
spiniform hrisiles on
both margins,

very slender, filiform,
naked, with only a
tuft of apical biistles,

Second pair of legs greatly produced; penulti-
mate joint dilated, and forming, togetlier w'ith
the last one, a kind of prehensile liand,

Thijsanopoda, il.-Edw.

Nyctiphanes, G. O. Sars.
Bentketiphmisia^ n. gen.

Thysanoessa, Brandt.
Nematoscelis, G. O. Sara.
Styloeheiron, G. 0. Sars.

Genus L Eupliausia, Dana, 1852.
Euphamia, Dana, United States Exploring Expedition, vol. xiii., Crustacea, part i. p. 639.

Generic Characters. — Carapace with autero-lateral angles Init slightly produced, rostral
projection, as a rule, small. Tail powerfully developed. Eyes of normal structure. Anten-
nular peduncle alike in both sexes, cylindrical, basal joint sometimes provided at the end
superiorly, with a small lappet ; both flagella elongate, and consisting of numerous joints.

G4 THE VOYAGE OF H.M.S. CHALLENGER.

Second pair of maxill;B with terminal joint verj- In-oad, exognatli comparatively small.
First pair of leg-s nearlj' similar in structure to maxillipeds and succeeding legs, save that
the terminal joint is somewhat expanded and armed with a fascicle of short spines. The
two last pairs of legs (piite ludimentary, being present only as minute, setiferous processes.
The four anterior jiairs of gills forming single, curved stems, fringed with a row of
narrow gill-sacs ; the three posterior pairs much more complex, sending oft' a branch
interiorlv; exterior l)ranch in last pair to a greater or less degree abundantly arliorescent.
The usual number of luminous globules present.

Remarks. — This genus was established by Dana, who distinguished it from the genus
Thysanojwda, M.-Edw., chiefly by the rudimentary character of the two posterior pairs of
less. This, indeed, would seem to be one of the most striking features bv which the
present genus may be distinguished from other genera of Euphausiidaj. Moreover, the
structure of the sills is somewhat different from that in other forms of this famih*.

The genus at present comprises no less than eleven different species, all of which are
represented in the Challenger collection. Of these, four only have been previously
recorded, the other seven being new. The Arctic species established by Kroyer under the
names of Tliysanopoda inermis, Thysanopoda neglecta, and TJiysanopoda longiccmdata,
which I previousl}' referred to the present genus, ought to be comprised within a distinct
genus, Boreopliatisia, G. 0. Sars, not represented in the Challenger collection.

Since the genus Euphausia may be regarded as the t}^)e of the family, I have
deemed it advisable, before passing on to the special description of the species, to give
a general account of its organisation, as gathered frohi a careful dissection of several
specimens belonging to one of the species, Euphausia peUucida, Dana.

General Description of the (j'enus. — The form of the liody (see PL XL figs. 1, 2 :
Pis. XIII.-XYI.) is generally rather slender, and somewhat compressed, ■^^-ith the tail
powerfully developed and always much longer than, sometimes even exceeding twice the
length of, the anterior division.

All the integuments are very thin and translucent, admitting of the muscles of the body,
and also certain of the viscera, being more or less distinctly traceable through them.

The carapace, as in other Euphausiidee, is comparativeh' small, leaving the bases of the
legs, with their gills, l)are, and posteriorly it does not completely cover the last segment
of the trunk, a portion of which always appears exposed above. Differing from all other
families of Schizopoda, it is, moreover, connate with the trunk along the whole of the
median line, in such a manner that none of the segments, excepting the last, appear
completely defined dorsally. Regarding its structure, it is very thin and pellucid,
without any kind of sculpture, save a slight transvei'se depression on its anterior part,
representing the cer\dcal sulcus. Posteriorly it exhibits in the middle a conspicuous
emargination, encompassing the exposed dorsal part of the last segment of the trunk.
The lateral wings of the carapace are evenly rounded, and project a, little over the sides

REPORT ON THE SCHIZOPODA. 65

of the first caudal segment, heiiig also purtiall)' overlapped hy a lamellar projection
extending anteriorly from this segment. The anterior part of the carapace is generally
slightly keeled above, and projects into a more or less marked rostral process. The
antero-lateral corners of the carapace are very slightly produced, exhibiting at the sides
of the basal part of the antenuse a small dentiform projection, apparently corresponding
to the autennal spine in other Podophthalmia.

The five anterior caudal segments are provided with distinctly developed lamellar
epimera, projecting beyond the ventral face and pointing oljliquely backwards. The last
segment is much narrower than the preceding ones, and rather compressed, without any
trace of epimera, but usually armed beneath its end witli a compressed tooth, placed
immediately anterior to the anal opening (preanal spine).

The eyes are well developed, and generally of a pyriform shape, having the pedicle
composed^of two segments, and the cornea expanded, globular, with a very dark pigment,
and distinctly develoj^ed visual elements. Moreover, the}' invariably contain within the
pedicle posteriorly and somewhat inferiorly a peculiar, highly luminous, organ (PI. XT.
figs. 7, h, 8), more fully described in the sequel. Between the bases of the eyes, too, maj'
be observed a small l)ut distinct spot of black pigment (the larval ej^e), apparently
containing anteriorly a minute refracting body (see PL XI. fig. 7, <i).

The antennular peduncle (see PI. XII. figs. 1, 2) is rather elongate, always projecting
far l)eyond the antennal scale, and cylindrical in form, with its three joints gradually
diminishing in size. The structure is precisely the same in both sexes. The basal joint
is somewliat flattened in its proximal part, and in some species exhibits at the end, above,
a small membranous lappet. Moreover, it is furnished with several finely ciliated
bristles, of which a dense fascicle is seen issuing from the outer corner. The last joint
exhibits a longitudinal keel, and exteriorlj^ at the end, a small lobe, from the base of
which issue two densely ciliated bristles. Both the flagella are rather elongate, though
far from attaining the length of the body, and consist of numerous small articulations.
The outer flagellum has at the l)ase a slight intumescence, l)eset with a fascicle of ti-ans-
luceut sensory bristles.

The basal part of the antenuse (see PI. XII. figw. 5, G) i« rather large, and divided
into two indistinctly defined segments, of which the proximal exhibits on the
ventral face a small opening, surrounded 1))' a somewhat tubular projecting border,
the outlet of the so-called "green gland." The distal segment juts forth at the
end exteriorly beneath the scale, as a more or less elongate spine. The terminal
part of the antenna consists of a rather elongate three-jointed peduncle and a slender
multi-articulate flagellum, somewhat longer than the flagella on the antennulje.
The scale is more or less elongate-ovate in form, having the outer edge straight and
naked, terminating also in a xexy small dentiform projection, sometimes, however,
obsolete. The apex is truncated, and, like the inner edge, fringed with a dense row

(ZOOL. CIIAIJj. EXP. PAHT -XXXVII. — 1885.) Oo 9

tJU THE VOYAGE OF H.M.S. CHALLENGER.

of ciliated setae. No trace of any apical articulation occurs either in this or in other
genera of Enphausiidse.

The anterior lip (see PI. XI. fig. G, I ; PI. XII. fig. 7) forms a triangular fieshy
prominence, placed between the basal parts of the antennae, and to some extent concealing
the inner ends of the mandibles. It projects anteriorly into a sharp point, and exhibits,
on the lower face, a thin transverse membrane, doubling over the l)ody from behind, and
•leeply incised in the middle.

The posterior lip (PI. XII. fig. 8) is formed of two membranous lobes, of triangular
form, separated by a deep incision almost to the base. The inner edges of these lobes
are finely ciliated throughout.

The mandibles (see PL XL fig. G, m ; PI. XII. fig. 9) have a rather strong, curved body,
with the masticatory part securiform-expanded. The cutting edge is armed wdth strong,
dentiform projections, somewhat difierent in shape on the two mandibles, and in recent
.specimens of a vivid reddish-brown colour. The molar prominence is well defined, and
has a rather extensive fluted surface. The palp (PI. XII. fig. 11 ; PL XIII. fig. 10 ;
PL XV. figs. 5, 15) scarcely exceeds the body of the mandible in length, and presents a
somewhat deviating form in the different species. It consists, as usual, of three joints,
of which the median is the largest, and is furnished with a moderate number of ciliated
bristles, those on the last joint sometimes assuming the character of spines.

The first pair of maxill* (PL XII. fig. 12; PL XIII. fig. 11 ; PL XV. figs. G, 16) exhibit
a somewhat difierent form from that observed in the other families of Schizopoda, being
furnished with both a well develoj^ed palp and an exognath. The basal part is divided
into two imperfectly defined segments, both of which j^roject inward as well marked
masticatory lobes. Of these lobes, the outer one is Ijy far the stronger, and abruptly
truncate at the end, which is furnished with a row of strong spines as well as a series of
delicate bristles. The inner or basal lobe is more decided!}^ membranous in consistence,
and somewhat linguiform, fringed along the anterior margin and at the rounded tip with
a row of strong setae, diminishing in length outwards. The palp, issuing from the distal
spgment of the basal part, and directed forw^ard, consists of a single lameUiform joint,
beset along the inner edge and tip with a double row of strong, ciliated bristles. Finally,
the exognath forms a rather large but very thin and pellucid plate of an oval, or rather
elliptical form, affixed to the outer side of the proximal segment of the basal part, and
fringed at the rounded anterior end with a few short bristles.

The second pair of maxUlte (PL XII. fig. 13 ; PL XIII. fig. 12 ; PL XV. figs. 7, 17)
also diff"er considerably in their general appearance from what is observed in other
Schizopods. Both of the masticatory lobes are very short and broad, and proceed directly
inward at right angles. They are slightly cleft in the middle, forming together four
densely setiferous lobes. The palp, as in the first pair, consists of only a single rather
large, lamelliform, joint, issuing from the end of the basal part and beset with bristles,

REPORT ON THE SCHIZOPODA. 67

more especially along the inner edge. The exognath, too, is very small, forming
simply a slight lamellar expansion of the outer edge of the basal part, and fringed
with a row of short, densely ciliated, bristles. The proximal portion of the basal part
forms a thick muscular segment, with the outer edge somewhat cui-ved, and in some
species furnished with a few bristles of a similar appearance to those affixed on the
exognath.

The maxillipeds (PI. XII. fig. 14) ai'e quite pediform in structure, and only to a very
slight extent differ from the succeeding true legs ; hence they have generally l)een
described by earlier authors as the first pair of legs. They consist of seven distinctly
defined joints, of which the two proximal correspond to the basal part of the maxillse,
whilst the others represent the palp. The first, or coxal, joint projects inwards into a
linguiform setose lobe (masticatory lobe), and in addition to this bears on its external
surface a very small, simple epipodite, corresponding, as regards location, to the gills on
the true legs. The second, or basal, joint is rather broad and compressed, exhibiting,
on the outer side, a distinctly developed natatory branch (exopodite) of precisely the same
appearance as the exopods on the legs. The ischial joint is somewhat broad, but gradually
tapers towards the apex. The meral joint is much more elongate and .slender, and forms,
in conjunction with the carpal joint, a rather mobile articulation, the outer part of the
maxilliped being generally, as in the legs, recurved almost at right angles to the
remaining part. The propodal joint is somewhat larger than tlie carpal, without,
however, attaining to anything like the length of the meral joint, and exhibits a linear
form, precisely as in these joints. The terminal joint, finally, docs not difi'er essentially
from the preceding joints, save that it is a trifle shorter ; it has, too, a row of short simple
bristles (see fig. 15) along its inner edge, besides two or three longer ones. All the
preceding joints are fringed along the inner edge, with a double series of delicate bristles,
those of the inner row being very long and lieset on both edges with small and somewhat
widely placed hairs. On the ischial and basal joints these bristles become shorter and
more numerous, assuming an almost spiniform character.

The first pair of legs (fig. 16) exhibit a very similar structure to that of the
maxillipeds. They are, however, a little longer, and have the terminal joint (fig. 17)
somewhat dilated and compressed. Each leg is also furnished at the inner edge with a row
of peculiar curved spines, densely crowded together, as well as a series of short ciliated
bristles. The inner lobe of the coxal joint is much swollen, and contains within a well
developed luminous globule. The epipod, too, has assumed the character of a true gill.
The exopod in this and the succeeding pair consists, as does the exopodite of the maxilli-
peds, of a muscular basal portion, and a lanceolate, compressed terminal part, fringed with
strong natatory setae ; the articulation between the two parts is very oblique, the basal
portion jutting out exteriorly at an acute angle.

The second pair of legs (fig. 18) are a trifle longer than the first pair, and only difter

68 Tin: voyage of h.m.s. challenger.

from these, in the coxal joint wanting the himinous globule, and in the terminal joint being
simply linear, and furnished with similar bristles to those on the preceding joints.

The three succeeding pairs of legs successively diminish in length, but exhibit other-
wise precisely the same structure as the second pair. The last of these pairs, or the fifth
in the series (fig. 19), has the joints somewhat more slender, and generally so bent that
the terminal part, when the legs are extended, curves in an opposite direction. The gills
attached to these legs are much more complex in structure than is the case with those on
the preceding pairs.

Of the two last pairs of legs no trace can be detected exteriorly. Only on dissecting
the animal and separating the two posterior pairs of gills (see PI. XL figs. 9, 11) does a
minute non-articulate stem, apparently the rudiment of the leg, become perceptible,
aflSxed to the inner side of each gill. This stem (fig. 12) is provided with a few simple
bristles, and would seem to represent the endopod rather than the exopod.

The gills (see PI. XI. fig. 5) are true " podobranchise," being attached to the outer side
of the coxal joints of the legs, and thus, apparently, representing the modifi-ed epipods.
There are seven pairs, wholly uncovered, as stated above, by the carapace, projecting at
some distance beneath its inferior margin, and arranged in a dense series along each side
of the trunk, partly overlapping each other posteriorly. They continue increasing in size
posteriorly, and the last pair are very much larger than any of the others, and partly project
along the sides of the first caudal segment. As to their structure, the four anterior pairs
(see PI. XII. figs. 16, 18, 20, 21) are much simpler than the three posterior, consisting
merely of an inferiorly and anteriorly curving stem, from which issues posteriorly a
regular series of slender, digitiform, or filiform appendages, diminishing gradually in length
towards the apex, which appears more or less curled up. These appendages, representing
the true gill elements, exhibit internally, in spirit specimens, a fairly regular double series
of small globular corpuscles (fig. 22), which, apparently, are blood-cells, arranged accord-
ing to the centrifugal and centripetal course they take through the appendages during
life. Tbe fifth and sixth pairs of gdls (PI. XI. fig. 9 ; PI. XII. fig. 19) are divided into
three branches, the two outer of which exhibit precisely the same structure as each of the
anterior gills, while the inner branch is distinctly bipinnate or furnished with a doulile
row of gill appendages. This branch, too, being the largest, is, as in the Lophogastridaj,
bent in beneath the trunk, meeting the corresponding branch on the opposite side in the
median line. Finally, the last pair of gills (PL XL fig. U) is far more complex in
structure than any of the others, the outer branch being very large, and more or less
richly arborescent; or it may send oft' numerous secondary bi-anches, each of which jire-

sents a similar .structure to that of the anterior oills.

In what manner the ova, immediately after being discharged from the ovaries, are
carried by the females of this genus, I am unable to state, none of the specimens

examined having been furnished with external ego-bao-s.

RErORT ON THE SCHIZOPODA. (J9

The camlal linilis (PI. XII. fig. 24) are powerfully developed in l)ot]i sexes, and repre-
sent true swimming organs. The basal part is somewhat adpressed and very muscular.
The terminal liranehes are shorter than the basal part, and exhil)it the form of lanceolate
plates, fringed with strong natatory sette. The inner plate (PI. XII. fig. 25) is rather
smaller than the outer, and exhiliits, as in most Caridea, a slender secondary lobe attached
to the inner edge, and ha\ ing at the tip a number of small curled spines (cincinnulaj).
In the male, this brancli on the two anterior pairs is peculiarly modified, to serve as
a copulatory organ (see PI. XL fig. 4). Especially on the first pair, this plate (PI. XII.
fig. 28 ; PI. XIII. figs. 3, 13 ; PI. XIV. fig. 7 ; PI. XV. fig. 22 ; PL XVI. figs. 6, 14, 20)
presents a verj^ complex structure, consisting of two principal portions, the outer
lamellar, and setiferous at the tip, and exhibiting on the posterior face a rounded pro-
jecting lobe, doubled over the plate ; whereas the inner juts out into several strongly
chitiuised processes of different forms, some assuming the shape of strong hooks or
pincers. This portion, too, is generally folded over the other in sudi a manner as to render
it a matter of some difficulty to spread out the whole plate in the same plane, with a view
of obtaining a correct idea of its structure. Of the two portions described above, the outer
oidy is found to correspond with the female plate, having likewise affixed to it the
secondary lobe mentioned above, whereas the inner portion is quite peculiar to the male,
since it constitutes another enormously developed lobe, extending above the former
from the inner edge of the principal plate. Also on the second pair of caudal limbs, the
inner plate in the male (see PL XII. fig. 29; PL XIII. figs. 4, 14 ; PI. XIV. fig. 8 ;
PI. XV. figs. 2, 3 ; PL XA^I. figs. 7, 15, 21) exhibits a somewhat diverging appearance ;
but here it would seem that the secondary lobe itself, which is common to both sexes,
becomes peculiarly modified, since it juts out at the apex into several twisted lobules,
generally reaching more or less beyond the tip of the principal plate ; the cincinnulse
occur on a slight rounded prominence at the outer side of the lobe. As to the function
of these remarkable appendages in the male, there can, 1 think, lie little doubt of their
serving to seize the spermatophores and place them on the sexual openings of the female.
The first pair are unquestionably most effective for this ])urpose, whilst the second pair
perhaps perform merely a coadjutory function.

The telson (PL XIL fig. 27) in all the species of this genus, as well as in the other
known Euphausiidse, exhibits a very similar appearance, being exceedingly slender and
tapering to an acute point. On the upper face two pairs of small denticles generally
occur, and on the lower face, at some distance from the apex, two very large spiniform appen-
dices are affixed in close proximity, slightly diverging and generally reaching far beyond
the tip of the telson. At the base of the telson, and likewise on the lower side, is seen
the anal opening, in the form of a longitudinal fissure.

The uropoda {H'id), too, only exhibit slight structural differences in the several
forms of the Euphausiida?. The l>asal part is rather short and thick, jutting out

70 THE VOYAGE OF H.M.S. CHALLENGEK.

externally as a small deutiform projection, and fringed at the outer edge with a row of
ciliated bristles. Both terminal plates are very slender, the outer, however, being some-
what broader than the inner, and of an oblong-linear form, with the outer edge naked
and straight, and terminating as a very small dentiform process, the apex narrowly
truncate, and, in common with the whole of the inner edge, having a row of long, ciliated
bristles. The inner plate is exceedingly narrow, conically tapered, and fringed through-
out with similar bristles. The length of the plates with respect to each other, as also to
the telson, varies somewhat in the difterent species, thus affording a comparatively good
specific criterion.

Luminous Globules. — These peculiar organs, for which I would suggest the above
designation, have not escaped the observation of earlier zoologists, and in part have even
been closely examined and described, most accurately by Professor Claus.^ In living
examples they are very conspicuous, and also in spirit-preserved specimens they admit of
being readily detected on dissection. The view generally favoured regarding the function
of these organs is, as is well known, that in some way they are subservient to sight,
whence they have been named by most authors "accessory eyes." I have carefully
examined these organs both in spirit specimens and in the living animal, and have
been led to form a very different opinion, conceiving them to have nothing whatever to
do with sight, but merely representing highly differentiated luminous organs. The.
reasons on which I base such an assumption wiU be set forth in the sequel. I shall first
describe the organs under consideration as they occur in the genus Euphausia.

In all the species of this genus, as also in most other Euphausiidae, they appear as
small globules, very conspicuous in the living animal by reason of their beautiful red
pigment and glistening lustre, and are symmetrically arranged both on the anterior and the
posterior divisions of the body. On the trunk are observed (see PI. XL figs. 1, 2) two
pairs of silch globules, the one situated within the coxal joint of the first pair of legs (see
PL XII. fio-. 16), the other within a corresponding dilatation issuing from the base of
the penultimate pair of gills (see PI. XL fig. 9). On the tail they occur along the
ventral face, in the median line, between the bases of the pleopoda, each of the four
anterior segments having a single globule. In addition to the above mentioned globules
may be observed, as stated above, within the pedicle of the eyes, an organ of somewhat
simdar appearance, though less completely developed (see figs. 7, 8). With the exception
of this last organ, all the others would seem to exhibit precisely the same structure.
Those most easy to examine without dissection are the hindmost pair on the trunk
(PI. XL fig. 10), as they lie in a position altogether external, immediately beneath the
inferior margin of the carapace. On placing the living animal under the microscope,
and applying a slight pressure by means of a cover-glass, in order to arrest its move-
ments, these organs admit of ])eing examined through a comparatively powerful

' Ueber einige Sehizopoden und niedere Malacostrakea Messina's, Zeilschr. f. vUs. ZooL, Bd. xiii. pp. 446, 447, 1863.

REPORT ON THE SCHIZOPODA. 71

magnifier, without any furtlicr preparatiuii. In .spirit specimens, somewhat greater
difficulty attends the research, since the transparency of the integuments, as also tliat of
the organ itself, is considerably diminislied by the action of the alcohol.

The organs, when isolated (see PI. XII. fig. 26), are found to consist of perfectly
globular bodies, with a very compUcated structure, bearing, in some particulars, great
resemblance to that of the eyes in vertebrates. A rather thick and elastic cuticle forms the
outer envelope of the organ, which, moreover, in fresh specimens is coated with a beautiful
red pigment in its posterior half, whereas the front portion remains quite pelluc;id. On
closer examination, these two portions are found to fit as it were into each other, without
being actually connate, and on dissecting alcoholic specimens, the two hemispheres will
even readily separate from each other. At the junction, a glistening ring may be seen
internall}-, encompassing in the middle a highly refractive lenticular corpuscle. The
posterior hemisphere is filled up with cellular matter, in the midst of which lies embedded
a flabelliform bunch of exceedingly delicate fibres, exhibiting in fresh specimens a most
beautiful iridescent lustre. To the equatorial zone of the organ, moreover, two or three
thin muscles are attached, admitting, to a certain extent, of its being rolled to and fro.

The above described parts are, it is true, of such a nature as might readily lead one
to assume that these organs are highly developed eyes. The lenticular corpuscle in
particular presents, both as regards its structure and its position, a striking resemblance
to a true eye-lens. The glistening ring too that surrounds it might easily be taken for
a kind of iris. The diaphanous front of the organ likewise and the red pigment coating
of the hinder part, as also the arrangement of the muscles for moving the whole organ,
would seem to favour such an assumption.

Notwithstanding this great resemblance to visual organs, researches conducted with
the living animal have convinced me that none of these organs are coadjutory to sight,
but that they all together constitute a very complicated and peculiarly developed luminous
or phosphorescent apparatus.

It has already been stated by W. Thompson that these Crustacea are highly luminous
at night, and for this reason he suggested for them the genei'ic name " Koctiluca." I
myself have several times had opportunities of testing the accuracy of this statement as
regards the Norwegian species of the family, and have convinced myself that the animal
is able, by varying the movements of the organs, to increase or diminish tlie light at
wdl. The chief light-producing matter I have found to be the fibrous fascicle lying in
the centre of the globular corpuscle. Even if the organ be crushed, and this fascicle
extracted, it still continues to give forth a comparatively strong phosphorescent light
when seen in the dark. The lenticular corpuscle placed just in front of this fibrous
matter may, I conceive, act as a condenser, producing a bright flash of light, the dii-ection
of which admits of being changed at the will of the animal, by simply rolling the organ
by means of its muscular apparatus. The pigment-coating of the hinder portion, and

72 THE VOYAGE OF H.M.S. CHALLENGER.

till' (lia]iliaii()iis condition df the front imrt, ma)' likewise be easily explained as subser-
vient to such a function.

That the organs in question cannot, as formerly held, be eyes, nuxy be inferred from
several facts : — 1. The nerve that penetrates the organs, or at least those belonging to
the trunk, is very thin, and does not give rise to any special (retinal) expansiori. 2. The
structure of the hinder part of the globule is wholly different from that observed in true
eyes, being comj^letely filled with a cellular mass, in the centre of which the fibrous
corpuscle lies embedded, and having its pigment-coating not internal but external.
3. The arrangement of the organs belonging to the tail is such, assuming the organs to
be eyes, as by no means to admit of a good visual impression, the constant motion of the
pleopoda approximating the organs at very short intervals, whereas the effect of phosphor-
escence may for that very reason be materially augmented, giving to the light a glitter-
ing or tremulous lustre. 4. Finall}', I have found, as stated above, a similar organ
embedded in the pedicle of the true eyes themselves, and this organ, being immobile, also
entirely lacks the front hemisphere with its lenticular corpuscle, whereas the hinder one
in every respect agrees with the posterior part of the other organs, exhibiting in the
centre a large liunch of })h()spliorescent fibres, and externally a coating of red pigment
(see PI. XI. fig. 8). It is certainly far from proliable that any one examining the last
of these organs would venture to assign it the function of sight ; and, indeed, Professor
Clans, who has recorded and figured the oroau in the larvae — in the adult animal it
would seem to have totally escaped his attention — has nothing whatever to state resj)ect-
ing its probable function. Meanwhile, the organ undoubtedly bears the closest relation to
the above described globules, both in regard to structure and function, the light it pro-
duces being, in fact, very intense, though comparatively more stead)-, than is that from
the other movable organs. Since the eye-pedicles, however, are themselves movable,
the animal may also, to a certain extent, be able to vary the effect of these organs.'

Nervous System (see PI. XII. fig. 30). — The nervous cord in the Eu])liausiidai exhibits
certain rather striking peculiarities as compared with that in other Schizopods. Thus, the
number of separate ganglia belonging to the anterior division of the body is greater than
in any other known form of podophthalmous Crustaceans, since, exclusive of the cerebral or
supra-oesophageal ganglion, no less than eleven ganglia occur, all of which, however, lie
embedded, as it were, within a common envelope of connective tissue. The most anterior
only of these ganglia, belonging apparently to the mandibular segment, would seem to
present all the features of a simple nervous dilatation, whereas the succeeding ones consist
of two well-marked lateral halves, and are connected by double and somewhat distant
commissures. Each of the two pairs of maxilte are innervated by their separate ganglion,
whereas these ganglia in most other Crustacea are, as is well-known, united and consoli-
dated with the mandibular ganglion into one nervous mass. The two posterior ganglia

' See N:uT. Chall. Exp., vol. i. p. 743, 18S5.

REPORT ON THE SCHIZOPODA. 73

of the trunk lie close together, at a considerable distance from tlie preceding ganglia, the
commissures being rather long, and also less distant, than are those connecting the
preceding ganglia.

Tlie supra-oesophageal or cerebral ganglion is rather large, and exhibits a somewhat
elliptical form, its transverse diameter being the larger. On its upper surface,
close to the anterior margin, is seen embedded the ocellus, or larval eye ; and
from each side proceed the greatly developed optic nerves, forming in the interior
of the eye-pedicles a large ganglionic tumescence, within which lies immersed the
previously mentioned luminous organ. Moreover, from the inferior face of the ganglion
originate two paii-s of strong nervous trunks, each of which exhibits at the base a con-
spicuous ganglionic swelling ; the one pair passes anteriorly in a direct line to the
antennulee, the other curves out exteriorly, entering the basal portion of the antennae.
The commissures connecting the cerebral ganglion with the first ventral are exceedingly
long and at a wide distance apart, encompassing the oesophagus, and are connected
together immediately behind it by a thin transverse commissure ; each, too, sends off
before its union with the mandibular ganglion a slender nerve, which passes apparently
to the stomach.

The caudal ganglia are by comparison exceedingly large, slightly exceeding even
those of the trunk, and are connected by very long commissures lying close together.
As is the case in Gnathophausia, and perhaps in most of the Podophthalmia, a pair- of
slender nerves, exclusive of the strong nerve-trunks originating from the ganglia them-
selves, extend from the commissures, apparently innervating the musculature of the tail.
Furthermore, from the last caudal ganglion originate numerous nerves, most of which
enter the caudal fan, innervating its various parts.

Digestive System (see Pi. XL fig. 5). — The oesophagus is very short, ascending per-
pendicularly to the stomach. Its walls would seem to be strongly chitinised, and are
continued into the inner (upper) coating of the anterior and posterior lips. The stomach
{st) lying, as usual, within the most anterior part of the visceral cavity in front of the
cervical groove, exhibits on the whole a similar structure to that in the Mysidai,
being armed, more particularly at the ventral face, with numerous chitiuous ridges, beset
with delicate bristles. Several strong muscles are attached to the stomach, by means of
which its several parts admit of being moved one against the other, thus crushing or
bruising the food before it is forced into the intestine. The pyloric section of the stomach
has above two small, incurving caica, and to its inferiorly protruding part is appended
the liver (/), in the form of two rather large ovoid masses, which are partly united, and
consist of a prodigious number of minute ca3ca, crowded together. The intestine {i) has
the form of an exceedingly narrow tube passing through the posterior part of the
trunk and the whole of tlie tail, and . terminating in a short rectum that opens at the
base of the telson throuoh a longitudinal fissure. In the livino- animal the whole

(ZOOL. CnALL. EXP. PART XXXVH. — 1885.) Oo 10

74 THE VOYAGE OF H.M.S. CHALLENGER.

intestine exliil)its very energetic and uninterrupted peristaltic and antiperistaltic move-
ments, giving it a peculiar moniliform aspect.

Circulatory System. — The heart (PL XL figs. 5, G, /;) is placed immediately beneath
the posterior part of the carapace, and exhibits a structure very similar to that observed
in the higher Podophthalmia, being rather concenti'ated, of a somewhat short polygonal
fonii, and furnished with six ^^airs of fissiform venous openings, for the entrance of the
blood accumulated in the pericardial sinus. Moreover, the number and arrangement of
the principal arterial trunks would seem to agree perfectly with that observed in higher
Crustaceans.

Generative System. — The ovaria (PL XL fig. 5, ov) form two partly connate masses
of a somewhat irregular ovoid form, placed beneath the heart, and projecting anteriorly
to a greater or less extent above the liver. They are found to contain numerous,
perfectly translucent egg-cells which vary in size, and from their lower face give origin
to two rather strong oviducts, extending straight downwards and opening close
together on the sternal part of the antepenultimate segment of the trunk. Here, too,
may often be seen afiixed two pedunculated vesicles, the spermatophores (PL XIIL
fig. 7).

The testes are combined as a comparatively small bunch of rounded, anteriorly point-
ing cseca, lying in front of the heart, immediately beneath the carapace. The vasa
deferentia are very long and flexuouse, extending posteriorly into the last segment of the
trunk, where they curve abruptly downward, and form a considerable dilatation (see
PL XL fig. 4), within which may be observed the developing spermatophore. The
latter exhibits in the present genus (see PL XIL fig. 23) a somewhat lageniform
appearance, being gradually dilated toward the apex, and possessing a highly chitinised
envelop. The spermatozoids constitute simple, elliptical, nucleate cells.

Habitat and Distribution. — All the known species of this genus are triily pelagic,
the animals being often found in great profusion swarming at the surface of the sea,
especially at night ; but in all probability they descend at times to considerable depths,
as is alleged to be the case with most other pelagic animals.

The genus would seem to be distributed throughout most parts of the ocean, except
perhaps the Arctic region, where it is represented by a closeh' allied generic type,
Boreoiohaiisia, G. 0. Sars.

REPORT ON THE SCHIZOPODA.

The following synopsis of the species may be here appended :-

Frontal part of
carapace

rather large, pyriform. ( two denticles,
Inferior margin of -<
carapace armed with ( a single denticle,

acutely produced.

Eyes

very small. Third
caudal segment

smootli, not pro-
duced, .

produced to an
acute pos-

teriorly curving
lappet.

very slightly pro-
duced. Inferior
margin of cara-
pace

smooth,

armed
with a
single
denticle
placed

anteriorly to the middle,

in the f smooth,
middle.

Third -{ produced to a pos-
caudal | tcriorly point-
segment [ ing spine.

produced to a strong rostral projection, and armed with distinct
supra-orlsital spines. Caudal segments partly spinous.

projecting as a
broad plate

( triangularly pointed,
( truncate at the apex,

E. pellucida, Dana.
E. similis, G. O. Bars.

E. (jracilis, Dana.

E. (jibba, G. 0. Sars.
E. siipnrba, Dana.
E. murrmji, G. O. Sars.
E. splendens, Dana.

E. nmcronata, G. 0. Sars.

E. spiniferu, G. 0. Sars.
E. antarctica, G. 0. Sars.
E. latifrons, G. 0. Sars.

14. Euphausia pellucida, Dana (Pis. XL, XII.).

Euj)liausia jyellueida, Dana, United States Expl. Exped., vol. xiii., Crustacea, p. G41, pi. xlii.

fig. 4, a-m.
Euphausia miilleri, Claus, Zeitschr. f. wiss. Zool., Bd. xiii. p. 432, pi. xxviii. figs. 29-31, pi. x.xix.
Thysanopoda Udentata, G. 0. Sars, Oversigt af Norges Crustaceer, Ikl. i. p. .50, pi. i.

figs. 11-U.
Euphausia pellucida, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 13.

Specific Charactei'S. — Carapace with two lateral denticles on either side, frontal part
produced, and. acutely pointed. Caudal segments smooth, epimera rather large and of
uniform appearance. Last segment longer than the preceding ; preanal spine tridcn-
tate. Eyes of moderate size, pyriform. Basal joint of antennulse with an erect leaflet
above, usually divided into two acuminate lappets. Antenna! scale oljlong-ovate,
obtusely truncate at apex, outer corner unarmed ; basal spine very large, and denticulate
at inner edge. Terminal joint of second pair of maxillaj short and broad, with a row of
small teeth anteriorly. Telson elongate ; subapical spines very large, and finely denti-
culate at inner edge. Inner plate of uropoda longer than outer. Usual length of adult
female 10 to 15 mm.

Remarks. — This would seem to be by far the commonest of all the Challenger species

7G THE VOYAGE OF 11. M.S. CHALLENGER.

of EiqjJicmsia, and, as it cannot reasonably be supposed to have escaped the attention of
Dana, I have deemed it advisable to refer the animal to one of the four species described
by that author. Of these, the species Euphausia jicllucida is the one that would seem
to agree best with the present form, for which, accordingly, I propose to retain the
specific appellation first suggested by Dana. That the Euphausia miillerl of Claus is
identical with the form here treated of is undeniable, and the form described by myself
as Tliysanopoda hidentata unquestionably also belongs to the same species.

Description. — The usual length of the adult female is 10 to 15 mm., that of the male
somewhat less ; but there are a few specimens in the collection that reach a length of
17 mm.

The form of the body (see PI. XL figs. 1, 2, 4) is rather slender, and, as usual,
somewhat compressed throughout, with the tail about twice the length of the anterior
division.

The carapace has the anterior part distinctly keeled above, and jutting forth as a
sharp-pointed rostral projection, reaching to about the middle of the basal joint of the
antennulje. Posteriorly it exhibits an almost rectangular emargination, the lateral
angles of which are produced into narrow sinuses, marking sharply off above the lateral
wings of the carapace, which are broadly rounded (see also figs. 5, 6). Immediately
superior to the lower margins on either side occur two small anteriorly pointing denticles,
the posterior of which is placed above the point of insertion of the fourth pair of legs,
the anterior above that of the maxillipeds. The antero-lateral corners of the carajiace
constitute at the side of the basal part of the antennae a very slight dentiform projection,
apparently corresponding to the antennal spine in other Podophthalmia.

The caudal segments are powerfully developed, and quite smooth aljove, diminishing
somewhat both in height and breadth posteriorly. The epimera are rather large and
laminar, projecting considerably beyond the ventral face, and covering at the sides the
bases of the pleopoda. They all exhibit a comparatively uniform appearance, being
somewhat angular in shape, and pointing obliquely backward. The last segment is a
trifle more elongate than any of the preceding, and much narrower, without any trace
of epimera, l)ut armed at the end, beneath, with a compressed, tridentate, pectiniform
spine (fig. 3), placed immediately in front of the anal orifice.

The eyes (fig. 7) are of moderate size, and pyriform, witli the cornea rather expanded,
and projecting on either side (see fig. 2).

The antennular peduncle (PI. XII. figs. 1, 2) is about half as long as the carapace,
and nearly cylindrical in form ; it is more particularly distinguished by the basal joint,
having at the end above a conspicuous erect leaflet or membranous lobe. In most of the
specimens this lobe is divided into two acuminate lappets (fig. 3) ; but in some speci-
mens, though differing in no other respect from the typical form, these lappets are much
more numerous, forming a dense fringe along the free edge of the leaflet (fig. 4).

REPORT ON THE SCHIZOPODA. / '

The antennal scale (fig. 5), Init very sliglitly projecting beyond the second joint
of the antenuular peduncle, exhibits an oblong-ovate form, its greatest breadth equalling
'about one-third of the length. The apex is abruptly truncate, with the outer corner
unarmed and well-nigh forming a right angle. The basal spine, projecting beneath the
scale, is very strong, and extends far beyond half its length ; it is armed at the inner
edge with a row of fine denticles. The basal part of the fiagellum reaches to the apex
of the scale, and is rather strong, with the two outer joints iiniform in size.

The mandibular palp (see figs. 9, 11) scarcely attains the length of the mandible
itself, and is specially distinguished by the middle joint Ijcing furnished (exclusive of
the usual marginal setae) with numerous short, spiniform bristles, arranged partly in a
double series along the inner side.

The first pair of maxillae (fig. 12) have the exognath comparatively small, and of an
oval form.

The second pair of maxillae (fig. 13) are distinguished more particularly l)y the short
and broad form of the terminal joint, which, moreover, exhibits anteriorly (apart from
the usual setae) a row of diminutive spiniform bristles similar to those on the mandil)ular
palp.

The maxillipeds (figs. 14, 15), the legs (figs. 16-19; PI. XI. fig. 12), and the gills
(PI. XII. figs. 19-22; PL XI. figs. 9, 11) exhibit the structure characteristic of the
o;enus.

The copulatory appendages projecting from the inner plate of the two first pairs of
pleopoda in the male (see PI. XI. fig. 4) are very powerfully developed. Those on the
anterior pair (PL XII. fig. 28) jut out into three strong processes, the two outer of
which are highly chitinised, and bent in the form of hooks ; one of them has the apex
simple-acuminate, whereas the other expands at the tip into a serrate oblong plate. The
appendages to the second pair of pleopoda (fig. 29) branch out into two soft, irregularly
lobular processes, reaching far beyond the tip of the principal plate.

The telson (see fig. 27) is very slender and elongate, almost ecpialling in length the two
posterior segments taken together, and has the apex produced to a lanceolate point. The
subapical spines are strongly developed, reaching far beyond the tip of the telson, and
divero-ing from each side ; they are also finely denticulate along their inner edge. INIore-
over, on the upper face, anterior to the point of insertion of the subapical spines, occur
two pairs of minute denticles, jtlaced at some distance from each other.

The uropoda (ibid.) do not nearly attain the tip of the telson, and have the inner
plate rather longer than the outer, but very much narrower.

Colour. — Dana states that this form, in a living state, is quite pellucid, without any
conspicuous pigmentation ; and hence he suggested the specific name " pellucida." The
soUtary specimen also, taken by myself ofi" the Norwegian coast, and at first described as
Thysanopoda bidentata, exhibited a perfect transparency throughout the whole bod)^

THE VOYAGE OF H.M.S. CHALLENGER.

Hahitat. — All the specimens of this species collected on the Challenger Expedition
were caught in the tow-net at the surface of the sea, in many different parts of the
ocean. As regards the localities, the date alone was, in most cases, recorded on the
labels, the tow-net having been on many occasions resorted to when neither dredging nor
trawling was carried on. Hence, the localities for this and other species of Euphausiidae
cannot in every case be referred to any of the actual Station numbers. To faciliate this
question, I have made an attempt in the following list to specify the tracts of the ocean
where the sjiccimens were caught, by comparing the dates recorded with the Stations
marked off on the majj accompanying the list of Observing Stations prepared for the
use of the naturalists engaged in furnishing an account of the voyage.

Date.

Locality.

June 18, 19, 1873.

North Atlantic, betweeu the Azores and Bermuda.

August 16, 1873.

Tropical Atlautic, ofl' African coast.

October 5, 1873.

South Atlantic, south-east of Rio de Janeiro.

December 19, 1873.

South of Cape of Good Hope.

August 11, 12, 1874.

Pacific, off Kandavu, Fiji Islands.

August 25, 26, 1874.

West Pacific, Api to Cape York.

(No date recorded.)

Australian Sea, Sidney to Wellington.

February 6, 1875.

Celebes Sea, off iMindanao, Philippine Islands.

February 1875.

North of New Guinea.

March 13, 1875.

North of New Guinea.

April 3, 187.5.

North Pacific, south of Japan.

June 23, 1875.

North Pacific, east of Japan.

.July 4, 1875.

North Pacific, further east.

July 1875.

North Pacific, Japan to Honolulu.

August and September 1875.

Trojjical Pacific, south of the Sandwich Islands.

August 24, 1875.

Tropical Pacific, south of the Sandwich Islands.

October 18, 1875.

South Pacific, about midway between New Zealand and Chili.

October 21, 1875.

South Pacific, about midway between New Zealand and Chili.

April 13, 1876.

Tropical Atlantic, off African coast.

April 26, 1876.

Tropical Atlantic, off St. Vincent, Cape Verde Islands.

April 28, 1876.

North Atlantic.

The specimens examined by Dana were collected in the Pacific, near Northern
Kingsmill Islands.

Distribution. — As shown by the above stated localitj,es, this species exhibits a truly
astonishing geographical range, having been met with in almost every tract of the
ocean traversed by the Challenger ; the North and South Atlantic, the Australian Sea,
Celebes Sea, and throughout the Pacific, from lat. 40° S. to lat. 40° N. It has, moreover,
been observed by Claus in the Mediterranean {Euphaitsia mUlleri), and ;i single specimen
of the same species was collected by myself off the Norwegian coast (Magerci) in lat.
63° 28' N.

REPORT ON THE SCHIZOPODA. 79

15. Euphausici sdmilis, G. 0. Sars (PI. XIII. figs. 1-G).

Euphausia similis, G. 0. Sars, Pieliminiiry Notices on the Challenger Schizopoda, No. 14.

Specific Characters. — Form of body somewhat more Mleuder tlian in the preceding-
species. Carapace with only a single, small, lateral denticle at the middle of tlie inferior
margin ; rostral projection rather produced, and very acute. Caudal segments smooth
above ; epimera of fourth and fifth segments small, and slightly emarginate inferiorly.
Last segment very elongate ; j^reanal spine diminutive, and simple. Eyes pyriform.
Antennular peduncle without any distinct dorsal leaflet. Antennal scale rather broad,
ovate, obliquely rounded at the apex, outer corner unarmed. Subapical spines of telson
much smaller than in Euphausia pellucida, and quite smooth. Inner plate of uropoda
shorter than outer. Length reaching 30 mm.

Remarks. — This species is very nearly related to Ettphausia pellucida, but attains
almost twice the size of that form. Moreover, the animal may easily be recognised by
the rostrum being considerably more produced, by ha^ang but a single lateral denticle on
the carapace, by the much shorter and perfectly smooth subapical spines of the telson,
and finally, too, by a somewhat different relation in length between the terminal plates
of the uropoda, as also by the simple structui'e of the preanal spine.

Desc7'iption. — Of the present species the collection contains but one specimen, an
adult male. It measures 30 mm., and hence has about double the length of the speci-
mens belonging to the preceding species.

The general form of the body (see PI. XIII. fig. 1) approximates to that of Euphausia
pellucida, though perhaps a trifle more slender.

The carapace has the anterior part but very slightly keeled above, and it runs out as
a comparatively long and very acute rostral projection, reaching beyond the middle of
the basal joint of the antennulse. On the inferior margin occurs but a single small
denticle, placed a little in front of the middle, or somewhat behind the base of the first
pair of legs.

The caudal segments are, as in the preceding species, smooth above, and taper
out gradually Ijackward. The three anterior pairs of epimera present the usual form,
and project not inconsiderablj', w^hereas the two posterior pairs exhibit a somewhat
difiierent aspect, projecting, as they do, a trifle less, and having the lower margin
slightly incurved, as also the •po^'^terior lobe narrowly produced. The last segment
is very elongate, and the preanal spine exceedingly small and quite simple, claw-
shaped.

The eyes (see fig. 2) are rather large and pyriform, with the cornea greatly expanded.

The antennular peduncle {ibid.) exhibits much the same appearance as in Euphausia
pellucida, but lacks any distinct dorsal leaflet, the basal joint forming at the extremity
above only a slight, well nigh imperceptible lobe.

80 THE VOYAGE OF H.M.S. CHALLENGER.

The auteuual scale (see fig. 2) is rather broad and oval in form, with the apex
obliquely rounded, and the outer angle unarmed. It projects scarcely at all beyond the
second joint of the antennular peduncle.

The copulatory appendages to the two first pairs of pleopoda (figs. 3, 4) difi"er some-
what in their structural details from those in Euplmusia pellucida. More especially in
the first pair, the diflerences are at once perceptible by comparing fig. 3 of this plate
with fig. 28 of PI. XII., the hook-shaped processes having a somewhat dissimilar form
in the two species.

The telson (see fig. 5) is very slender, and distinguished from that in Eupliausia
jjellucida more particularly l)y the suljapical spines being much smaller and quite
smooth.

As in the preceding species, the uropoda (ibid.) do not attain the length of the
telson ; and as regards the terminal plates — contrary to the relation in Euphcmsia
■pellucida — the inner are appreciably shorter than the outer.

Habitat. — The above described specimen was taken with the trawl, in the South
Atlantic, south-cast of Buenos Ayres, having in all probability been brought up from
some intermediate stratum of the sea during the hauling up.

Station 320, February 14, 1876; lat. 37° 17' S., long. 53' 52' W. ; depth, 600
fathoms.

16. Euphausia splendens, Dana (PL XIII. figs. 7-17).

Eupliausia sjilenderis, Dana, United States Expl. Exped., vol. xiii., Crustacea, p. 642, pi. xlii.

fig. 5, a~h.
Euphausia splendens, G. O. Sars, Preliminaiy Notices on the Challenger Schizo})oda,

No. 1.5.

Specifxi Characters. — Form of body somewhat more robust than in the last two
species. Carapace with a single denticle about the middle of the lower margin ; anterior
part slightly keeled above ; rostral projection remarkably short, scarcely projecting
beyond the ocular segment. Caudal segments smooth above ; epimera rather small and
evenly rounded. Last segment longer than preceding ; preanal s^^ine simple. Eyes
rather large, pyriform. Antennular peduncle without any trace of dorsal lobes, but with
a fascicle of very strong curved setse, springing from off the dorsal face of the basal joint.
Antennal scale nearly as in Euphausia p)Mucida; basal spine, however, much shorter.
Terminal joint of second pair of maxillse very large, and ovate in form. Subapical spines
of telson smooth. Inner plate of uropoda a little shorter than outer. Length reaching
18 mm.

Remarks. — As the descriptions of Dana are anything but satisfactory', it is some-
what difficult to decide ^\'itli absolute certainty whether this form be in fact identical

REPOET ON THE SCHIZOPODA. 81

with the Eiqihausia splendens of that author, or belong to some other alUed species.
Meanwhile, assuming the species so designated by Dana to Ije almost certainly repre-
sented in the rich collection of the Challenger Euphausiida;, I hold this form to be the
one most properly referaljle to that species. From both the preceding species the
present form may be readily distinguished by its robust body, the very short rostral
projection, and the strong, curving setse that spring from the basal joint of the
antennulae.

Description. — The length of the largest specimen reaches about 18 mm., and the
species attains accordingly a somewhat larger size than Euphausia 2)eUucida.

The general form of the body (see PL XIII. fig. 7) would, on the whole, appear to be
somewhat shorter and more thickset than in the two preceding species, and this feature,
too, is obvious from the figure given by Dana, at least as comiJared with that of Euphausia
j)ellucida.

The carapace, as in Euphausia similis, exhibits on either side a single lateral
denticle about the middle of the lower margin, or rather just above the point of insertion
of the second pair of true legs. Its anterior part has above a well-marked keel, and the
frontal margin forms in the middle a very slight rostral projection, or rather an acute
angle, scarcely projecting beyond the ocular segment.

The caudal segments are smooth above and furnished with rather small evenly
rounded epimera. The last segment is appreciably longer than any of the preceding, and
has the preanal spine (fig. 17), as in Euphausia similis, quite simple or unguiform, though
somewhat stronger than in that species.

The eyes (see fig. 15) are very large and projecting, pyriform, with the cornea much
expanded.

The antennular peduncle (fig. 8) is more particularly distinguished by the total absence
of any dorsal leaflet or lobe, whereas a bunch of strong, curving bristles is seen to spring
from the dorsal face of the basal joint.

The antenna! scale (fig. 9) agrees in its form comparatively well with that in
Euphausia pellucida, though perhaps a trifle more elongate. The basal spine, as in that
species, is distinctly denticulate, but very much smaller.

The mandibular palp (fig. 10) exhibits none of the short spiniform bristles peculiar to
Euphausia pellucida.

The first pau" of maxillae (fig. 11) have the exoguath relatively larger, and more
oblong in form.

The second pair of maxillae (fig. 12) are chiefly distinguished by the large size and
ovoid form of the terminal joint.

The copulatory appendages of the two first pairs of pleopoda in the male (see figs. 13,
14) exhibit on the whole a structure considerably approximating to that in Euphausia
similis. Still, however, a few well-marked difi"erences may be found, more especially in

(ZOOL. CHALL. EXP. PART XXXVII. 188.').) Oo 11

82 THE VOYAGE OF H.M.S. CHALLENGER.

the form of the three hook-shaped processes on the appendages of the first pair, as shown
in tlie respective figures (compare figs. 3 and 13).

The telson and uropoda (fig. 16) would not seem to differ essentially from those parts
in Eiiphausia similis.

Colour. — According to Dana, this species, in a living state, is more 'or less tinged with
red or purple, especially along the ventral face of the body.

Habitat. — The specimens in the collection were taken at the surface of the sea in the
following localities, as shown in the table : —

Date.

Locality.

December 17, 18, 1873.
October 21, 187.5.
January 21, 1876.
February 11, 1876.

Off Cape of Good Hope.

South Pacific, about midway between Kew Zealand and Chili.

South Atlantic, Cape Virgins to Falkland Islands.

South Atlantic, Falkland to ISuenos Ayres.

The specimens examined by Dana were collected in She tropical region of the
Atlantic (lat. 2° N.).

Distribxition.- — The distribution of the present species, as yet known, would accord-
ingly seem to be chiefly restricted to the southern parts of the Atlantic and Pacific
Oceans.

17. Eupliausia imtrrayi, G. 0. Sars (PL XIV. figs. 1-4).

Eupliausia raurrayi, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 16.

Specific Cliaracters. — Form of body somewhat more slender than in Eiqyhausia
splendens. Carapace rather elongate, with a single lateral denticle, placed in front of the
middle of the inferior margin ; anterior part very slightly keeled above ; rostral projection
short ; frontal margin forming on either side, above the eyes, an obtuse angle. Caudal
segments smooth above, with rather deep epimera, the posterior pair triangular, produced
posteriorly. Last segment not much longer than preceding ; preanal spine obsolete.
Eyes short and thick, claviform. Antennular peduncle pro^dded above at the end of the
basal joint with an anteriorly pointing lobe, obliquely emarginate at the tip. Antenna!
scale oblong, truncate at apex, denticle of outer angle very small. Gill-trunks very
broad and flattened, with numerous exceedingly slender, well-nigh filiform lobules.
Telson with three pairs of dorsal denticles ; subapical spines smooth. Inner plate of
uropoda very slightly overreaching outer. Length attaining 43 mm.

Remarks. — Next to Eupliausia superha, this Eupliausia, is the largest in the coUec-

REPORT ON THE SCHIZOPODA. 83

tion, and admits of Ijeing distinguished from Euphausia splendens, to which form it
bears a close relationship, — except in its much larger size, — l)y a somewhat more slender
form of body, the comparatively shorter eyes, the presence of a well-marked cuticular
lobe at the end of the basal joint of the antennula3, the peculiar expanded form of the
gills, and finally by the form of the posterior pair of caudal epimera.

Description. — Of this species, the collection has two specimens, the larger of which
reaches a length of 43 mm. Both are females.

The form of the body (see PI. XIV. fig. l) would seem to be a trifle more slender
than in Euphausia splendens; the anterior division in particuhir is appreciably more
elongate as compared with the posterior.

The carapace, as in Euphausia splendens, has on either side a distinct lateral denticle,
which, however, occurs somewhat in front of the middle of the lower margin. Its
anterior part is very slightly keeled above, and marked off by a distinct cervical impres-
sion. The rostral projection (see fig. 2) is very short and triangular, l)ut slightly over-
reaching the ocular segment, and, moreover, rather sharply defined from the frontal
margin, which on either side exhibits an obtuse angle above the eyes.

The caudal segments are smooth above, and provided with rather deep, irregularly
rounded epimera. Those on the penultimate segment are, however, somewhat dissimilar,
being rather produced in the form of acute, triangular plates, pointing backwards and
overlapping the last segment. This, too, is but very little, if at all, longer than the
preceding, and does not exhibit any trace of a preanal spine.

The eyes (see fig. 2) are rather short and thick, almost clavate, and but slightly
projecting on either side.

The antennular peduncle (ibid.) is comparatively elongate, and has a distinct
cuticular lobe projecting, above, from the end of the basal joint, as also another much
smaller one, exteriorly, at the end of the second joint. Both the lobes are extended
horizontally, and exhibit a somewhat triangular form, the larger one is also obliquely
emarginate at the tip.

The antennal scale (ihid.) projects a little beyond the second joint of the anten-
nular peduncle and has a rather elongate, oblong-linear form, with the apex narrowly
truncate and the denticle of the outer corner very small, though quite distinct.

The giUs (fig. 3) are characterised hj a somewhat unusual form of the trunk, which
is greatly expanded and flattened, well-nigh semilunar, and has aflixed to the outer
convex edge a very considerable number of exceedingly slender, nearly filiform gill-
lobules. The posterior pairs of gills (see fig. 1) are richly arborescent, exhibiting an
abundance of cui-ved secondary lu-anches.

The telson (see fig. 4) exhibits the usual slender form, and has three pairs of small
dorsal denticles. The subapical spines were broken in the larger specimen; in the
smaller one they are of moderate size and quite smooth.

84 THE VOYAGE OF H.M.S. CHALLENGER.

The uropoda (see fig. 4) reach very nearly to the tip of the telson, and have the inner
phite projecting sliglitly beyond the outer.

Habitat. — The two s})ecimens secured were taken at the following localities : —

Date.

Locality.

January 27, 1874.
February 19, 1874.

Southern Oceau, off Kerguelen, in trawl, 96 fathoms.
Antarctic Ocean (Station 154), near ice-barrier.

Distribution. — The distribution of the species, as yet known, would accordingly
seem to be restricted to the Southern and Antarctic Oceans.

18. Euphausia suioerba, Dana (PL XIV. figs. 5-9).

Eupliausia superlia, Dana, United States Exploring Expedition, vol. xiii., Crustacea, p. 645,

pi. xliii. fig. 1, a-o.
Eupliausia superba, G. 0. Sars, Preliminary jSTotices on the ChaUeuger Sohizopoda, No. 17.

Specific Characters. — Body rather compressed. Carapace narrow, without any lateral
denticle ; anterior part scarcely at all keeled above ; rostral projection very small, and
obtusely rounded. Caudal segments smooth above, with very large epimera. Last
segment short, not longer than preceding ; preanal spine obsolete. Eyes large, pyriform.
Antennular peduncle very strong, having above, at the end of the basal joint, a small,
cordiform lobe. Antennal scale comparatively short, ovate, apex obliquely rounded.
Exopods of legs, as also pleopods, very powerfully developed. Gills well-nigh as in
Eupliausia murrayi. Telson with apex very slightly produced ; subapical spines slender
and smooth. Uropoda reaching beyond tip of telson, inner plate shorter than outer.
Length attaining 48 mm.

Remarks. — There cannot, I think, be any doubt whatever as to the identity of the
form treated of here with Dana's EupjJiausia superba, and, moreover, the specimen in the
collection had been labelled with that name by the late Dr. v. Willemoes-Suhm. It is
readily distinguished from all the preceding species, not only l^y its large size, but also by
the very short and obtuse rostral projection, the absolute want of lateral denticles on the
carapace, the remarkably thick antennular peduncles, and the powerful development lioth
of exopods and pleopods.

Description. — The solitary specimen procured during the Expedition is an adult male,
measuring 48 mm. in length.

The general form of the body (see PI. XIV. fig. 5) is as in Eupliausia mxirrayi,
though comparatively more compressed.

The carapace is rather narrow, and lacks every trace of lateral denticles, and,

REPORT ON THE SCHIZOPODA. 85

moreover, does the anterior part exhibits no distinct keel above. Tlie rostral projection
(fig. 6) is exceedingly short, reaching but very slightly beyond the ocular segment,
and the frontal margin does not form any angle above the eyes, as in the preceding
species.

The caudal segments are very powerfully developed, and, as in the preceding species,
smooth above. The epimera are rather deep and irregularly rounded in form, except the
posterior pair, which, as in Enphausia murrayi, are triangular* and produced. The last
segment does not exceed in length the preceding, and would seem to lack the preanal
spine.

The eyes (see fig. 6) are very large and protruding, pyriform, with the cornea very
much expanded.

The antennular peduncle {ibid.) exhibits an exceedingly robust structure, and has
a well marked cordiform lobe, projecting above from the end of the basal joint.

The antennal scale {ibid.) is comparatively short, scarcely reaching to the end of
the second joint of tlie antennular peduncle ; it exhil)its an oval form, with the apex
somewhat obliquely rounded and the denticle of the outer corner very small, almost
obsolete.

The gills (see fig. 5) would, on the whole, seem to agree in structure with those
of Euphausia murrayi.

The exopods on the maxillipeds and legs, as also the pleopods, are very powerfully
developed, more so than in any other known species.

The copulatory appendages to the first pair of pleopoda (fig. 7) closely resemble those
in Euphausia splenden.s ; still, however, some few differences in detail may be discerned.
Thus, for example, the outer process and the secondary hook of the inner one are cpiite
simple, and strongly curved, whereas these parts in Euphausia splendens are bidentate
at the apex. The appendages of the second pair of pleopoda (fig. 8) are comparatively
shorter, reaching but very little beyond the apex of the principal plate.

The telson (see fig. 9) is comparatively shorter than in the other species, with the
apex very slightly produced and ol)tusely pointed. The subapical spines are exceedingly
slender and quite smooth.

The uropoda (ibid.) reach somewhat beyond the tip of the telson, and have the inner
plate appreciably shorter than the outer.

Colour. — According to the statements of Dana, this species, in a living state, is
characterised by a very conspicuous colouring, the whole body, save the legs and gills,
l:)eino; tino;ed with a brilliant red.

Habitat. — The above described specimen was taken at the surface of the sea, along
with the larger specimen of Euphausia tmirrayi, February 19, 1874, in the Antarctic
Ocean, at Station 154. Dana ol)tained this species, too, in the Antarctic Ocean, south
of Van Diemen's Land, in lat. GG° 5' tS., long. 157° E.

SQ THE VOYAGE OF H.M.S. CHALLENGER.

19. Euphausia antarctica, G. 0. Sars (PI. XV. figs. 1-8).

Euphawsia antarctica, G. 0. Sars, Preliminary Notices on tlie Challenger Schizopoda, No. 18.

Specific CJiaracters.— Form of body rather slender, with tail less powerful in
development than is generally the case. Carapace without any lateral denticle ; anterior
part slightly keeled above and projecting as a broad, triangular, frontal plate. Caudal
seo-ments smooth above, with remarkably small, rounded epimera. Last segment
slightly exceeding in length the preceding, wth a minute, simple, preanal spine. Eyes
claviform. Autennular peduncle slender, without any dorsal lolje, but with the outer
corner of the basal joint produced into a sharp spine. Antennal scale oblong-linear,
obtusely truncate at apex, outer corner jutting out as a well marked dentiform pro-
jection. Mandibular palp remarkably slender, with terminal joint linear. Last joint of
second pair of maxillse oblong-ovate. Legs very elongate and densely setose. Telson
with three pairs of dorsal denticles ; subapical spines moderate in size, smooth. Uropoda
much shorter than telson, inner plate slightly overreaching outer. Length 17 mm.

Remarks. — This is a rather anomalous form, and readily distinguished , from all
the other species by the remarkably narrow tail and very slender legs, as also by the
broad triangular frontal plate and the form of the antennal scale.

Description. — All the specimens collected are females, and the largest measures aliout
17 mm. in length.

The form of the body (see PL XV. fig. l) is rather slender, and the proportion
between the anterior and posterior divisions somewhat different from that observed in
most of the other species, the tail being relatively far less powerfully developed.

The carapace lacks every trace of lateral denticles, the inferior margin being c[uite
smooth and but very slightly incurved along their anterior part. The antero-lateral
angles of the carapace project considerably and are acutely angular; the frontal
part (see fig. 2) protrudes over the base of the eyes as a Inroad horizontally extending
plate of triangular form, reaching nearly to the middle of the liasal joint of the
anteunulfe. From the base of the plate, a slight dorsal keel is seen to extend backwards
along the anterior part of the carapace.

The caudal segments are smooth above and rather narrow, the epimera being
comparatively very small and evenly rounded. The last segment but slightly exceeds
in length the preceding, and has a very small, simple preanal spine (fig. 4), mostlj*
hidden between the bases of the uropoda.

The eyes (see fig. 2) project considerably, Ijut have the cornea not very much
expanded, with the greatest breadth aliovit the middle of the pedicle.

The antennular peduncle {ibid.) is comparatively slender, and lacks every trace
of dorsal lobes, but has the outer corner of the l)asal joint jutting forth as a shai"]^),
spiniform projection.

REPORT ON THE SCHIZOPODA. 87

The antennal scale (see fig. 2) exhibits a foi-m somewhat difierent from that in the
other species, being rather elongate, oblong-linear, and projecting a little beyond the
second joint of the antennular peduncle. The apex is obtusely truncate, and the outer
angle juts out into a well marked, dentiform projection.

The mandibular palp (fig. 5) is ver}' slender, its terminal joint being nearly as long
as the median, l)ut very much narrower, linear, and armed with six spiniform bristles,
increasing gradually in length toward the apex.

The first pair of maxillse (fig. 6) have the exognath very large and oval in form, but
in other respects resemble those of Etiphausia splendens.

The second pair of maxUlae (fig. 7) are more particularly distinguished l)y the
remarkable size and oblong-ovate form of the terminal joint.

The legs are very slender and elongate, the ischial joint Ijeing much the largest, and
in the fifth pair (fig. 8) exceeding in length even all the succeeding joints taken
together. They are, moreover, furnished with a very dense fringe of remarkably long
and delicate setaj.

The gills (see figs. 1, 8) would seem, on the whole, to agree comparatively closelj'
in structure with those of Euphausia pellucida.

The telson (see fig. 3) about equals in length the two posterior segments taken
together, exhibiting a somewhat less slender form than in the other species, rather
flattened throughout and tapering but slightly, with the apex lanceolate. It is armed
with three pairs of very small dorsal denticles, exclusive of the sul)apical spines, which
are rather strong and smooth.

The uropoda {ibid.) are much shorter than the telson, and have the inner plate
slightly projecting beyond the outer.

Habitat. — Of this species, numerous specimens were collected in a single locality, ^az.,
at the ice-barrier in the Antarctic Ocean. They were, as usual, taken in the tow-net,
at the sui-face of the sea. The locality is as follows : —

Station 153, February 14, 1874 ; lat. G5° 42' S., long. 79° 49' E.

Moreover, several very young specimens and larvse, apparently of the same
species, were collected in two other localities near that stated above, viz., at Stations
152 and 156.

Hence there cannot, I think, be the slightest doubt as to this species constituting a
form quite peculiar to the Antarctic region.

20. Euphausia miccronata, G. 0. Sars (PL XV. figs. 9-11).

Euphausia mucronata, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 19.

Specijic Characters. — Form of bod}- as in Euphausia splendens. Carapace with a
single lateral denticle, about the middle of the inferior margin ; anterior part having a

SS THE VOYAGE OF H.M.S. CHALLENGER.

well-marked rounded crest above ; rostral projection very short. Caudal segments with
fully developed epimera ; third segment jutting out posteriorly as a strong dorsal spine,
pointing backwards. Last segment rather elongate ; preanal spine obsolete. Eyes
very lar"e, pyriform. Autennular peduncle without any dorsal lappet. Antennal
scale oblong, apex narrowly truncate, outer angle unarmed. Telson elongate, taper-
ino-, with two pairs of dorsal denticles ; subapical spines strong and diverging,
smooth. Inner plate of uropoda scarcely at all projecting beyond outer. Length
reaching 14 mm.

Remarks. — Tiiis species somewhat resemljles Euphausia splendens. It may, however,
at once be distinguished by the strong spiuiform projection of the third caudal segment,
a character from which the specific name is derived.

Description. — The specimens in the collection are not in the best state of preservation,
l)ut yet distinctly exhibit the prominent characters of the species. AU of them are
females, and the largest specimen has a length of about 14 mm.

The form of the body (see PI. XV. fig. 9) approximates, on the whole, a good deal to
that of Euphausia sjilendens, the tail being powerfully developed and weU nigh twice
the length of the anterior division.

The carapace has on either side a distinct lateral denticle, placed about the middle of
the inferior margin, or above the point of insertion of the second pair of legs. The
anterior part exhibits a very conspicuous' rounded dorsal crest, and juts out as an
exceedingly short rostral projection, reaching but little beyond the ocular segment.

The caudal segments have rather deep epimera, of a rounded form, except the last
pair, which are triangular. The third segment juts out dorsally into a well-marked,
mucroniform spine, pointing backwards, and at the end of the penultimate segment
a simdar but very small projection occurs. The last segment is rather produced,
about as long as the two preceding ones taken together, and would seem to lack the
preanal spine.

The eyes (see fig. 10) occur very large and protruding, pyriform, with the cornea
greatly expanded.

The autennular peduncle (ibid.) does not exhibit airy distinct dorsal lappet. A
very small protrusion of the anterior margin of the basal joint may, however, possibly be
considered the rudiment of such a part.

The antennal scale {ibid.) reaches a little beyond the second joint of the auten-
nular peduncle, exhibiting an oblong form, with the apex narrowly truncate and the
outer angle unarmed.

The oral parts and the legs would not seem to difter materially from those of
Euphausia splendens.

The telson (see fig. 11) is rather elongate, and tapers graduaUj- toward the apex,
which is lanceolate and pointed. The subapical spines are strong and di^'erging, but

REPORT ON THE SCHIZOPODA. 89

quite smooth. Moreover, two pairs of small dorsal denticles occur on the posterior half
of the telson.

The uropoda (see fig. 11) are much .shorter than the telson, and have the terminal
plates uniform in length.

Habitat. — This species was ol)tained on November 18, 1875, in the South Pacific, ofi"
the coast of Chili, where a few specimens were taken at the surface of the sea.

21. Exiphaiisia gracilis, Dana (PL XV. figs. 12-23).

Euphausia gracilis, Dana, United States Exploring Expedition, vol. xiii., Crustacea, p. 644, pi. xliL

figs. 6, a-e.
Euphausia gracilis, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 20.

Specific Characters. — Form of body very slender and elongate. Carapace with a
single lateral denticle about the middle of the inferior margin ; anterior part very
slightly keeled above ; rostral projection sharply pointed. Caudal segments smooth
above, with very small rounded epimera. Last segment rather elongate ; preanal
spine simple. Eyes remarkably small, with the cornea scarcely at all expanded.
Antennular peduncle without any dorsal lappet, basal joint shorter than the other two
taken together. Antennal scale oblong-ovate, apex obtusely truncate, outer corner
unarmed. Gills rather simple in structure, with biit few digitiform lol)ules. Telson
with two pairs of dorsal denticles ; subapical spines smooth. Inner plate of uropoda
much longer than outer, and reaching the tip of the telson. Length ahout 10 mm.

Remarks. — This form is without doubt the Euphausia gracilis of Dana, and in every
way entitled to its .specific designation, being by far the most slender species of the
genus. Moreover, the animal can be recognised by its remarkably small eyes.

Descri2)tion. — The length would not seem to exceed 10 mm., and accordingh-
the present species must take rank among the smallest belonging to this family.

The form of the body (see PL XV. fig. 12) appears exceedingly slender; tlie taU in
particular is very elongate, attaining, as it does, more than twice the length of the
anterior division.

The carapace is rather narrow, and exhilnts on either side a single lateral denticle,
placed about the middle of the inferior margin, or, more precisely, just above the point
of insertion of the second pair of legs. Its anterior part is very slightly keeled
above, and juts out as an acutely pointed rostral projection, reaching considerably
beyond the ocular segment.

The caudal segments are quite smooth above, and have the epimera very small
and rounded, but slightly projecting beneath the ventral face. The last segment is
very elongate and compressed, even a trifle longer than the two preceding segments

(ZOOL. CnALL. EXP.— PART XXXVII. — 1885.) Go 12

90 THE VOYAGE OF H.M.S. CHALLENGER.

taken together. The preanal spiue (fig. 19) is exceedingly narrow and acutely

pointed.

The eyes (see fig. 20) are distinguished by their remarkably small size, and almost
fusiform shape, the cornea not being at all expanded, and the greatest thickness occurring
in the middle of the pedicle.

The antennular peduncle (fig. 13) does not exhibit any trace of dorsal lappets.
The basal joint is rather broad, but shorter than the two succeeding joints taken
together. The middle joint forms at the end, above, a slight projection, reaching
over the base of the terminal joint, and provided -with a dense row of delicate
bristles.

The antennal scale (fig. 14), slightly projecting beyond the second joint of the
antennular peduncle, exhibits an oblong-ovate form, wdth the apex narrowly truncate
and the outer corner unarmed. The basal spine is rather elongate, reaching nearly to
the middle of the scale, and is armed at the inner edge with a row of strong denticles.
The basal part of the flagellum appears rather powerful, but does not nearly attain the
length of the scale.

The mandibular palp (fig. 15) has the terminal joint very small and oval in form ;
it is armed with five ciliated spines on the inner edge, and a single bristle on the
outer.

The first pair of maxillsB (fig. 16) exhibit much the same appearance as in Euphausia
antarctica.

The second pair of maxilla (fig. 17) have the terminal joint not very large, of
a rather regular ovoid form, and but sparingly supplied with bristles.

The maxillipeds and legs exhibit, on the whole, the usual structure, and have the
outer joints somewhat flattened.

The gills are comparatively simple in structure and provided vidth a somewhat
limited numl^er of digitate lobules. The posterior pair (fig. 18), which, in other species,
are richly arborescent, consist of only three comparatively short branches, one of which
is bent inwards.

The copulatory appendages to the two first pairs of pleopoda in the male are rather
strongly developed. Those on the first pair (fig. 22) have the outer process securiform,
or projecting into two hook-shaped processes, pointing in opposite directions ; the
middle one is strongly bent, and finely dentate at the tip ; the inner process finally has
the secondary hook serrate at the outer edge. The appendages of the second j^air
(fig. 23) jut out into three rather broad and somewhat twisted lobes, reaching considerably
beyond the apex of the principal plate.

The telson (see fig. 21) exhibits the usual slender form, and is armed with two pairs
of small dorsal denticles, exclusive of the subapical spines. The latter (broken oft' in the
specimen examined by Dana) are rather strong, Imt quite smooth and slightly divergent.

REPORT ON THE SClilZOPODA.

The uropoda (see fig. 21) have the inner plate much longer than the outer, and,
when exserted posteriorly, reaching the tip of the telson.

Colour. — -According to Dana, the animal, in a fresh state, is quite pellucid, without
any distinct pigment.

Habitat. — A good many specimens of the present species were collected by the
Expedition in different tracts of the ocean. They were all taken at the surface of the
sea. The following is a list of localities, with the dates at which the specimens were
obtained : — ■

Date.

Locality.

August 16, 1873.

June 8, 1874.

August 25, 1874.

February 6, 1875.

August to September, 1875.

AprU 26, 1876.

Tropical Atlantic, off African coast.

Australian Seas, off Port Jackson.

West Pacific, Api to Cape York.

Celebes Sea, off Mindanao.

Tropical Pacific.

Tropical Atlantic, off St. Vincent, Cape Verde Islands.

Dana took this form in the Pacific, lat. 15° 23' S., long. 148° 23' W.
Distribution. — Hence the species would seem to occur chiefly in the tropical parts of
the Atlantic and Pacific Oceans, ranging southward to the Australian Seas.

22. Euphauda gibba, G. 0. Sars (PL XVI. figs. 1-8).

Euphauda (jihha, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 21.

Specific Characters. — Form of body very slender. Carapace with a single lateral
denticle, placed behind tlie middle of the inferior margin ; rostral projection acutely
pointed. Tail gibbous in the middle, with the third segment projecting, posteriorly, as an
acute dorsal lappet, overlapping the succeeding segment. Last segment very elongate ;
preanal spine simple. Eyes rather small, slightly expanded at the tip. Basal joint of
antennula3 with a very small bifid lappet at the end above. Antennal scale rather large,
oblong-ovate, apex obtusely truncate, outer corner unarmed. Telson as in Euphausia
gracilis. Inner plate of uropoda scarcely at all extending beyond outer, and not
reaching tip of telson. Length about 1 5 mm.

Remarks. — In its external form this species very closely resembles the preceding,
but may, on closer examination, be easily recognised by the peculiar gibbous form of the
tail and the dorsal lappet projecting from its third segment.

Desoiption. — The largest specimens attain a length of 15 mm., and hence the species
slightly exceeds the preceding one in size.

92 THE VOYAGE OF H.M.S. CHALLENGER.

The form of the Ijody (see PI. XVI. fig. 1) is very slender, though perhaps less so
than in Eiqyhausia gracilis.

The carapace is very similar iu form and structure to that of Eiiphausia gracilis,
with this exception, however, that the lateral denticle does not occur iu the middle of
tlie inferior margin, having a somewhat posterior position, just above the point of
insertion of the third pair of legs. The rostral projection (see fig. 2) would appear to be
a trifle narrower and very acute.

The caudal segments are on the whole more powerfully developed than in the
preceding species, the epimera being also larger and more projecting inferiorly. The
third segment in all the specimens forms a very conspicuous angle with that succeeding
it, giving to the tail in the middle, as it were, a geniculate appearance or gibbous character,
precisely as in several Caridea, for example the genus Hippolyte. As in that genus,
moreover, an acutely pointed lappet is seen to project posteriorly from the dorsal face of
the third segment, arching over the base of the following segment, to which it is closely
applied when the tail is fully extended. The last segment, very elongate and slightly
compressed, is about as long as the two preceding segments taken together. The pre-
anal spine is nearly the same as in Eupliausia gracilis, though in some examples a small
secondary tooth occurs at its base.

The eyes (see fig. 2) are comparatively very small, but have the cornea distinctly
expanded, whereby they acquire a more regular pyriform shape than in Eiiphausia
gracilis.

The antennular peduncle (ibid.) exhibits a structure very similar to that of the
preceding species, with this exception, however, that a small bifid lappet (fig. 4) occurs
at the end of the basal joint above.

The antennal scale (fig. 5) is rather large, reaching appreciably beyond the second
joint of the antennular peduncle ; it appears, too, relatively broader as compared with
that in Euphausia gracilis, and has an ovate form, with the apex obtusely truncate and
the outer corner unarmed. The basal spine is very slender, and, as in Euphausia
gracilis, denticulate along the inner edge.

The oral parts and the legs would not seem to exhibit any essential difi"erence from
those of Euphausia gracilis.

The gills are comparatively more fully developed, being furnished with a greater
number of lobules, and the last pair (fig. 8) have five lobuliferous branches.

The copulatory appendages to the first pair of pleopoda in the male (fig. 6), although
developed much as in Euj^haiisia gracilis, still show well-marked specific differences in
their structural details. Thus, the middle process exhibits a very extensive development,
being highly chitinised, and bent in the middle to a hook-shaped form, whereas the two
other processes are comparatively feeble in structure. The appendages of the second
pair of pleopoda (fig. 7) difi'er but slightly from those in Euphausia gracilis.

REPORT ON THE SCHIZOPODA. 93

The telson (see fig. 3) exhibits almost exactly the same structure as in Euphausia
gracilis.

The uropoda (ihid.), ou the other hand, differ essentially as regards the inner plate,
which is relatively shorter, scarcely at all exceeding in length the outer, and do not
nearly reach the tip of the telson.

Habitat. — Of this species, too, the collection comprises comparatively numerous
specimens, all of which were taken at the surface of the sea. The following is a list of
the localities, with the dates at which they were obtained : —

Date.

Locality.

February to March, 1873.
August 11, 12, 1874.
August 2.'?, 187-4.

Atlantic, between Tenerife and St. Thomas.
Pacific, off Kandavu, Piji Islands.
West Pacific, Api to Cape York.

The distribution of the species would, therefore, seem to be much the same as that of
the preceding species, comprising, as it does, the tropical regions of the Atlantic and
Pacific Oceans.

23. Euphausia spinifera, G. 0. Sars (PI. XVI. figs. 9-16).

Euphausia spinifera, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 22.

Specific Characters. — Form of body somewhat robust. Carapace with, a very strong,
lateral denticle, placed in a sinus above the inferior margin, a trifle posterior to the
middle ; anterior part provided with an elevated crest forming midway an erect denticle ;
rostral projection remarkably strong, straight, acuminate ; frontal margin armed with a
pair of sharp-pointed supra-orbital spines. Caudal segments with large epimera ; third
segment projecting posteriorly as a sharp, mucroniform, dorsal .spine; posterior margin of
the two succeeding segments divided into several sharp-pointed laj^pets. Last segment
elongate ; preanal spine bidentate. Eyes short and thick. Antennular peduncle with a
broad, indented lappet projecting from the basal joint above. Antennal scale oblong-
linear, narrowly truncate at apex, outer corner projecting as a well-marked tooth.
Telson very slender, with five paii-s of small dorsal denticles ; subapical spines finely
denticulate at inner edge. Uropoda much shorter than telson, inner plate extending
slightly beyond outer. Length reaching 26 mm.

Remarks. — This is a very distinct species, and easily recognised by the remarkably
strong rostral projection and the spiny armature both of the anterior and posterior
divisions of the body.

94 THE VOYAGE OF H.M.S. CHALLENGER.

Description. — Four specimens only of this form were collected, the largest of which,
a male, has a length of 26 mm.

The form of the body (see PL XVI. fig. 9) appears much more robust than in the two
preceding species, and a good deal compressed.

The carapace is rather short in proportion to its height, and has on either side,
posterior to the middle, a very strong denticle, which, however, does not, as is generally
the case, project from the inferior margin, but occurs at some distance above it, arching
over a sinus, from which a ridge extends anteriorly, joining the margin at the side of
the mandibles. The anterior part of the carapace is provided with a very marked dorsal
crest, jutting out in the middle as an erect tooth. The rostral projection is remarkably
strong, projecting horizontally as a sharp dagger-like process, reaching nearly to the
end of the basal joints of the antennulse. Above the eyes, moreover, the frontal margin
juts out, on either side, as a well-marked, somewhat upturned dentiform projection, or
supra-orbital spine.

The caudal segments are powerfully developed, and provided \\'ith rather large
lamellar epimera. Of these the two anterior pairs are almost quadrangular, whereas
the three posterior ones exhibit a more pronounced triangular form, their posterior angle
being slightly produced. The third segment, as in Euphausia mucronata, projects
posteriorly as a strong dorsal spine, pointing straight backwards, and has, moreover,
extending from the posterior margin, on either side an angular lobe. Again, the two
succeeding segments are distinguished by their posterior margin being di^dded into
several pointed lappets, one of which occupies the median line dorsally. The last
segment is much narrower and more elongate than the other, although not attain-
ing the length of the two preceding segments taken together. The preanal spine
(fig. 16) is distinctly bidentate, or has a rather strong secondary tooth at the posterior
edge.

The eyes (see figs. 9, 10) are very short and thick, almost globular, with the cornea
exceedingly expanded.

The antennular peduncle (ibid.) is rather slender, and distinguished more par-
ticularly by the presence of a broad, but very thin and membranous, dorsal lobe,
extending from the end of the basal joint and overlapping the base of the succeeding
joint. This lobe, too, is divided at the edge into several acute lappets (see fig. 12),
somewhat irregularly disposed, and forming two or three bunches. Another and very
much smaller lobe is found to project from the second joint, being almost spiniform in
shape, with a small lateral lappet proceeding from the outer edge (see fig. 13).

The antennal scale (see fig. 10) projects appreciably beyond the second joint of
the antennular peduncle, and exhibits an oblong-linear form, with the apex narrowly
truncate and the outer corner jutting out as a well marked dentiform projection.

The oral parts could not be more closely examined for want of sufficient specimens.

REPORT ON THE SCHIZOPODA. 95

The structure of the maxillipeds and the legs, as also that of the gills, would seem
not to differ essentially from that observed in the other species of the genus.

The coijulatory appendages to the two first pairs of pleopoda in the male (see figs. 1 4,
15) are in every respect normal in structure, although certain slight specific difi'erences
can indeed be found b}" comparing them with those parts in other species.

The telson (see fig. 11) is very slender and elongate, attaining the length of the two
preceding segments taken together, and exhibits no less than five pairs of minute dorsal
denticles. The subapical spines are of moderate size, reaching but slightly beyond the
lanceolate tip of the telson, and have theu- inner edge finely denticulate.

The uropoda (ibid.) are much shorter than the telson, and have the inner plate
very narrow and only slightly overreaching the outer.

Habitat. — The four specimens procured, three of which have been mounted in
glycerine on glass slides, were taken at the surface of the sea, in the following
localities :—

Date.

Locality.

May 9, 10, 1874.
October 21, 1875.
October 22, 1875.

South of Australia, lat. 48° 18' S., long. 30° 11' E.

South Pacific, about midway between New Zealand and ChilL

South Pacific.

The distribution of this species as yet known, would accordingly seem to comprise the
southern part of the Pacific Ocean.

24. Euphausia latifrons, G. 0. Sars (PI. XYI. figs. 17-23).

Euphausia lafifrons, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 23.

Specific Cliaracters. — Form of body rather short. Carapace without any lateral
denticle ; rostral projection very peculiar in shape, forming, as it docs, a broad, quadrate
plate abruptly truncate at the apex. Caudal segments smooth above, with comparatively
small, rounded epimera. Last segment longer than preceding, and jutting out at the
end dorsally as a short dentiform projection; preanal spine small, unguiform. Eyes
clavate, cornea but slightly expanded. Antennular peduncle with a short serrate lobe
extending from the basal joint above. Antennal scale subovate, apex rounded, outer
corner armed with a distinct tooth. Telson with three pairs of dorsal denticles, subapical
spines serrate along the inner edges. Inner plate of uropoda reaching slightly beyond
outer. Length scarcely exceeding 8 mm.

Remarks. — The small size of this animal, in conjunction with the peculiar shape of
the frontal plate, induced me at first to regard it merely as a larval stage of some other

90 THE VOYAGE OF H.M.S. CHALLENGER.

form of Euphausiidaj. On closer examination, however, I felt convinced of its consti-
tuting a new and peculiar species of the genus Eitphcmsia, that retained, so to speak, in
the adult state, certain apparently larval characteristics. After the plate had been
printed, I found among specimens of Euphausiidae from Port Jackson, a few male
examples of somewhat larger size than the one here figured, but, for the rest, closely
agreeing with it in all essential characters. The most striking feature in the present
species is unquestionably the very peculiar form of the frontal projection, from which
character, indeed, the specific denomination has been derived.

Description. — None of the specimens exceed a length of 8 mm., most indeed are
rather smaller, and hence the species may be regarded as a true pigmy form.

The body (see PI. XVI. fig. 17) is rather short, the tail measuring about twice the
length of the anterior division.

The carapace has no trace of lateral denticles, the inferior margin being quite smooth
and slightly incurved. The anterior part does not exhibit any distinct keel above ; it
projects as a broad, well nigh quadrate plate, arching over the base of the eyes, and
reaching about the middle of the basal joint of the antennuhie. This plate, too, is slightly
hollowed along the middle, and at the apex abruptly truncate, or sometimes even slightly
emarginate, with distinctly projecting lateral corners.

The caudal segments are smooth above and provided with comparatively small,
rounded epimera. The last segment is a trifle more elongate than the preceding, and
juts out at the end above as a small dentiform projection (see fig. 22). The preanal
spine is very small, and unguiform.

The eyes (see fig. 18) exhibit a somewhat clavate form, having their greatest
thickness in the middle of the pedicle, the cornea not being at all expanded.

The antennular peduncle (ibid.) is provided at the end of the basal joint above, with
a very thin and membranous lobe (see fig. 19), serrate at the edge and overlaj^ping the
base of the succeeding joint. The outer corner of the basal joint is, moreover, drawn
out to a strong, anteriorly pointing spiiie.

The antennal scale (see fig. 18) scarcely projects beyond the second joint of the
antennular peduncle, and exhibits an oblong-ovate form, with the apex narrowly
rounded and the outer corner drawn out to a distinct, although short, dentiform
projection.

The oral parts and the legs do not seem to exhibit any essential structural pecu-
liarities.

The gills are, on the whole, not particularly] developed, the digitate lobules being
in comparison few in number and the posterior pairs but slightly arborescent.

The copulatory appendages to the first pair of pleopoda in the male (see fig. 20) diff"er
somewhat in structure from those in other species of the family, being, on the whole,
much simpler, and without the strong hamiform processes generally observed. They

REPORT ON THE SCHIZOPODA. 97

consist merely of three thin membranous phites, of wliich the median is the longest, and
quite unarmed, whereas the outer one exhibits two short spiniform Itristles at the apex ;
the inner plate is very narrow, and may strictly be regarded as the secondary lobe of the
principal plate. The appendages to the second pair of pleopoda (see fig. 21) are more normal
in structure, l)ut rather small, projecting slightly beyond tlie apex of the principal plate.

The telson (see fig. 22) is of the usual slender form, \\ ith three pairs of small dorsal
denticles. The subapical spines (see fig. 23) are rather strong, and have the inner edges
finely denticulate.

Habitat. — The specimens procured during the Expedition were collected at the surface
of the sea in the following localities : —

Date.

Localitj'.

April 4, 1874.
June 8, 1874.
September 13, 1874.
October 23, 1874.

Off south-east coast of Australia.

Australian Seas, oil' Port Jackson.

Arafura Sea.

Celebes Sea, off Mindanao, Philippine Islands.

The distribution of the species would accordingly seem to be restricted to the
Australian Seas and those of the Indian Archipelago.

Genus 2. Thijsanopoda, Milne-Edwards, 1830.

Tliysanopoda, ]\Iilne-Ed wards, Ann. d. Sci. Nat., t. ,\i.x.

Generic Cha^xtcters. — General aspect as in Euphausia. Flagella of Ijoth paii's of
antennae greatly elongate. Exognath of second pair of maxillae very small. Maxillipeds
and anterior pairs of legs nearly as in Euphausia. Penultimate pair of legs distinctly
developed, and of the same structure as the preceding ; last pair with the endopod
obsolete, but having a well-developed exopod. All the true gills provided with an
interiorly bent branch ; the two posterior pairs rather complex in structure, last pair
much the larger and richly arborescent. Luminous globules as in Euphausia.

Remarks. — The present genus — that first established in the family — was founded on
a form procured from the Atlantic and described by Milne-Edwards under the name of
Thysanopoda tricuspidata. Neither this t}'pical species, nor other forms strictlv
belonging to the present genus, have been recorded by any sul)sequent naturalists ; for
all the forms since described as Thysanopods ought, in my judgment, to l)e referred to
different genera of the family. The present genus — in the restriction here adopted — is
chiefly characterised by the penultimate pair of legs being fully developed and having a
structure quite similar to that of the preceding paii's, whereas in the last pair the endopod
is wholl}^ wanting, the exopod only being of normal development. ]\Ioreover, in the

(ZOOL. CIIALL. ESP. — P.\nT XXXVII. — 1885.) Oo 13

THE VOYAGE OF HiM.S. CHALLENGEE.

structure of tlie gills the genus shows marked differences as compared with other
EuithausiidfB. In addition to the tyi:)ical species first described by Milne-Edwards,
three other very distinct si:)ecies, apparently belonging to this genus, are represented in
the Challenger collection, and will be described more in detail in the sequel. I give here
a synopsis of the four species as yet known to belong to this genus.

Carapace -

with two strong lateral denticles. Eostral projection sharply pointed,
and having posteriorly at its base a flattened, forward-pointing
spine. Tail with the four hind segments produced posteriorly to
short dorsal spines, ......

with a single lateral denticle. Rostrum short, acuminate. Carapace
and tail smooth above. Eyes remarkably small, .

without any

lateral denticles.

Frontal part

obtusely rounded,
above,

Caudal segments smooth

produced to a distinct compressed rostrum and
having an elevated crest above. Fourth and
fifth caudal segments produced posteriorly to
small dorsal denticles.

T. ti-icuspidata, M.-Edw.
T. microphthalma, n. sp.
T. ohtusifrons, G. 0. Sars.

T. cristata, G. 0. Sars.

25. Tlnjsanopoda tricuspidata, Milne-Edwards (PL XVIL).

Thysanopoda triciispndata, Milne-Edwards, Ann. d. Sci. Xat., t. xix. ]>. 451, pi. xix.
Tlii/sanopoda tricusjndata, Milne-Edwards, Hist. nat. des Crustaces, t. ii. p. 463, pi. xxvi.

figs. 1-6.
Thysanopoda tricuspjidafa, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, Xo. 24.

Specific Characters. — Body rather slender, with the tail slightly bent in the middle.
Carapace armed with two strong lateral denticles at the inferior margin ; frontal part
produced to a sharp-pointed rostrum, and having above, in the middle, a flattened
anteriorly directed spine. Third caudal segment projecting posteriorly as a strong
dorsal spine ; the three posterior segments armed with similar, but much smaller spines.
The two anterior pairs of caudal epimera curved anteriorly ; first pair very large and
divided into two acuminate lappets. Last segment rather elongate ; preanal sjjine
bidentate. Eyes large and projecting, pjTiform. Autennular peduncle slender,
cylindrical, with a small narrow lanceolate lappet at the end of the first and second
joints above. Antennal scale oblong-linear, apex narrowly rounded, outer corner
jutting out as a small denticle. Penultimate pair of legs much smaller than preceding.
Telson with four pairs of dorsal denticles, apex greatly produced, and armed close to the
tip with two pairs of exceedingly minute secondary teeth ; svibapical spines of moderate
length, smooth. Uropoda shorter than the telson, inner plate a little longer than the
outer. Length 24 mm.

Remarks. — 1 have felt some douljt in referring this form to the typical species, as
neither the very strong spine on the third caudal segment, nor the peculiar flattened
spine of the carapace, behind the rostrum, has been represented in the figure given in

REPORT ON THE SCHIZOPODA. 99

Milne-Edwards' work. Ou the other hand, this figure shows distinctly another feature,
very chai-acteristic of thepreseut species, and not found, so far as I know, in any other
form, viz., the peculiar shape of the two anterior pairs of caudal cpimora. Moreover, in
several other respects, for example, in the form of the maxillae, the present animal agrees
perfectly with iMilue-Ed wards' species, and hence I cannot but regard them as identical.

Description. — Most of the specimens collected are rather small, and apparently not
yet full grown ; but there is in the collection one specimen — a female — much larger than
■ the others, and measuring 24 mm. in lengtli. This example, which, I Ijelicve, has attained
its full size, is represented in PL XVII. fig. 1, whereas the anatomical figures were pre-
pared from one of the smaller specimens.

The form of the l)ody (see fig. 1) is rather slender and somewhat compressed, with
the tail, in all the specimens, exhibiting a marked bend in the middle, the three posterior
segments being more or less deflexed, forming an obtuse angle with the anterior ones.

The carapace is rather deep in its posterior part, and exhibits on either side two
strong and rather distant denticles projecting from the inferior margins, the anterior
placed just above the point of insertion of the maxillipeds, the posterior above the base
of the penultimate pair of legs. The anterior part of the carapace is much narrower
than the posterior, and juts out as a sharp-pointed rostral projection, reaching bej'ond
the middle of the basal joint of the antenuula3. Immediately beneath the base of this
projection occurs a very minute denticle, and on the dorsal face, a little l)ehiud the
rostrum, is seen a rather strong and somewhat flattened spine, pointing straight forwards.

The caudal segments are powerfully developed, and provided with rather large
epimera. Of these, the two anterior pairs curve forwards, whereas the three posterior
ones are dii-ected obliquely backwards, having the posterior angle somewhat produced.
The first pair of epimera are much the lar'gest, and exhibit a rather peculiar form, being,
as it were, divided into two acute and anterior curving lappets, the posterior of which is
the larger and provided with a small secondary tooth at the inferior margin ; the anterior
lappet would seem to be partly overlapped by the hinder margin of the carapace. The
four posterior segments project at the end, above, as well-marked acute spines, pointing
backwards, of which that of the third segment is much the largest. The last segment
is rather elongate, with the preanal spine distinctly developed, and armed at the base
with a small secondary denticle.

The eyes (see fig. 2) are very large and protruding, pyriform, with the cornea con-
siderably expanded.

The antennular peduncle (fig. 5) is comparatively slender, and almost cylincbical in
form, with the basal joint about as long as the two others taken together. It exhibits
aliove two very narrow lanceolate lappets, the one extending from the end of the basal
joint, the other originating from the second joint. Moreover, the outer corner of the
basal joint is drawn out to a strong forward-pointing spine.

100 THE VOYAGE OF H.M.S. CHALLENGER.

Tlic aiitrimal scale (see fig. 6) projects but very slightly beyond the second joint of
the antcnnidar peduncle, and exhibits an oldong-linear form, Avith the apex narrowly
rounded and tlie outer corner jutting out as a small but distinct dentiform projection.
The basal spine is very narrow and quite smooth, and the basal part of the flagellum
slender, with the two outer joints equal in length.

The anterior and posterior lips (figs. 7, 8) differ but slightly in structure from those
of Euphausia, nor do the mandibles (fig. 9) show any characteristic feature, their
palp being relatively small, with the last joint oblong in form.

Tlie first pair of maxillae (fig. 10) are more particularly distinguished by the unusually
small size of the exosnath, which for the rest exhibits the usual structure.

The second pair of maxillae (fig. 11) have comparatively a slight development, with
the exognath almost obsolete and the terminal joint ovate.

The general structure of the maxillipeds (fig. 12) and of the five anterior pairs
of legs (figs. 13-15) agrees very nearly with that in Euphausia. On the other hand,
the two last pairs exhibit very marked diflerences.

The penultimate pair of legs (fig. IG), which in Euphausia are quite rudimentary,
are developed precisely as the preceding pairs, exhibiting, as they do, the full number of
endopodal joints, together witli a fully developed exopod. In the present species, this
pair, however, is somewhat smaller than the preceding, having the meral joint scarcely
longer than the ischial, and the terminal part (three last articulations) much shorter than
the meral joint.

The last pair of legs (see figs. 17, 17 a) want every trace of an endopod, but have the
exopod in every respect normally developed.

The gills (figs. 17, 20-25) exhibit certain well marked differences in structure as
compared with those in Euphausia. With the exception of the simple epipodal lobes,
which in this genus, as in Eupjhausia, are affixed to the maxillipeds (see figs. 12, 19), and,
in a strict sense, correspond to the true branchiae, all of them exhibit a secondary branch,
springing from the main stem at the base interiorly, and backwards gradually becoming
more developed. On the gills belonging to the two first pairs of legs (figs. 20, 21) this
branch, in the specimen dissected, was quite simple, and in appearance similar to that of
the gill-lobules arising from the outer edge of the curved stem. On the succeeding pair
(fig. 22) the branch w^as considerably larger, and exhibited two short lateral lobes on either
side. That of the fourth pair of gills (fig. 23) had three well-developed lobes on either
side, besides a smaller one at the base. On the fifth pair of gills (fig. 24), too, three
bipartite lobes have made their appearance at the base of the branch, in addition to the
six simple ones; and on the sixth (penultimate) pair (fig. 25) two of these basal lobes
had assumed a structure similar to the main stem (or outer branch), l)eing fringed along-
one of the edges with a row of well-developed gill-lobules. The last pair of gills (see fig. 1 7)
are much larger than any of tlic preceding, and consist of two principal stems pointing in

REPOET ON THE SCHIZOPODA.

101

opposite directions, both of which, but more particuhirly the outer one, are furnished witli
numerous secondary branches beset with reguhir rows of gill-lobules. It should, however,
be noted, that the specimen submitted to dissection was not yet full grown, and accord-
ingly the gills here figured may be strictly somewhat less complex than in adult animals.

The caudal linil)s, or pleopoda (fig. 18), do not differ in their structure from those in
other Eupliausiidte.

The telson (see fig. 3) exhibits the usual slender form, tapering gradually toward the
apex, which is muc^h produced and drawn out to a very acute point. On examining this
point under a high magnifying power, it is found to be armed on either side with two
very small secondary teeth (see fig. 3a). Moreover, on the dorsal face of the telson
four pairs of small .denticles occur, disposed at regular intervals. The subapical spines
project but very slightly beyond the tip of the telson, and are (pxite smooth.

The uropoda {ibid.) are shorter than the telson, and have the inner plate a trifle
longer, but much narrower than the outer.

The luminous globules agree in every respect, as to number, arrangement, and
structure, with those of the genus Eajphausia.

Habitat. — The specimens of this form collected during the Expedition were taken at
the surface of the sea in two different localities : —

Date.

August 11 to 12, 1874.
August 25, 1874.

Localit}'.

Pacific, off Kaudavu, Fiji Islands.
West Pacific, Api to Cape York.

Exclusive of these specimens having the aspect peculiar to the adult animal, the
characteristic larval form of this species (to be described further on) has been met wdth
in many other localities, showing the distribution of the species to be rather extensive.
I annex a list of localities : —

Date.

Locality.

August 23, 1873.
January 9, 1875.
February 6, 1875.
February 187.5.
August 24, 1S75.

Tropical Atlantic (Station 104).

Ofif Luzon, Philippine Islands.

Off Mindanao, Celebes Sea.

West Pacific, north of New Guinea.

Pacific, 400 miles south of Hawaii, Sandwich Islands.

August .30, 187.5.
September 12, 1875.
March 21, 1876.
April 6, 1876.
May 12, 1876.

Tropical part of Pacific.
Tropical part of Pacific.
South Athmtic (Station 338).
Tropical part of Atlantic.
North Atlantic.

102 THE VOYAGE OF H.M.S. CHALLENGER.

The specimen examined by Milne-Edwards — a full-grown female — came from the
Atlantic. Hence the species would seem to inhabit the tropical regions of the Atlantic
and Pacific Oceans, sometimes, however, occurring to the north and south of the tropical
zone.

26. Thysanopoda obtusifrons, G. 0. Sars (PI. XVIII. figs. 1-14).

Tlujscuwpuda ohtusifvons, G. 0. Sars, Preliminary Notices on the Clialleuger Schizopoda, No. 25.

Specific Characters. — Form of body rather stout, not very much compressed.
Carapace without lateral denticles or dorsal crest, frontal part slightly produced, but
obtusely rounded, not forming any distinct rostral projection. Caudal segments smooth
above, with epimera of moderate size, none anteriorly curved, the three middle pairs
slightly sinuate at the inferior edge. Last segment longer than preceding ; preanal
spine obsolete. Eyes very small. Antennular peduncle remarkably strong, with rather
a large and densely hispid lappet projecting from basal joint above, and overlapping
base of second joint. Antenna! scale broad, ovate, with apex rounded and outer corner
unarmed ; basal portion of flagellum very strong and massive. Terminal joint of first
pair of maxillae exceedingly narrow, that of second, on the contrary, very large and
broad. Penultimate pair of legs but very little shorter than preceding, with meral
joint very elongate. Outer branch of anterior pairs of gills exceedingly small. Telson
ha-ving above two parallel serrate keels, apex bluntly lanceolate, subapical spines strong
and diverging. Inner plate of uropoda shorter than outer. Length reaching 23 mm.

Remarks. — The present form, although difi"ering in its general form very appreciably
from the typical species, should unquestionably be regarded as a true Thysanopoda,
agreeing, as it does, comparatively closely in all the essential anatomical features adduced

as characteristic of that generic type.

Description. — Only three specimens of this form were secured, one of which I saw
fit to sacrifice for dissection, with the object of determining the generic relationship of the
.species. The largest of the specimens measures 23 mm. in length.

The form of the body (see PI. XVIII. fig. 1) would appear to be rather stout, and

not compressed by far to the same extent as in the preceding species, both the carapace

and the tail occurring broadly rounded above.

The carapace does not exhibit any trace of lateral denticles, the inferior margin

being quite smooth and slightly incurved in its anterior part. A very slight keel occurs
; above on the anterior part, but no trace of any cervical impression can be detected. The

frontal part projects somewhat in the middle above the liases of the eyes, without,

however, forming any true rostrum, the end of the projection being obtusely rounded off"

(see fig. 2).

The caudal segments arc quite smooth above, and have the epimera of moderate size

REPORT ON THE SCHIZOPODA. 103

and of tlie usual form, none of tliem exhibiting a peculiar development. The three middle
pairs are slightly sinuate at the infciior edge, whereas the last jiair have a rounded
triangular form, with the posterior angle produced. The last segment is somewhat
elongate, without any distinct preanal spine.

The eyes (see fig. 2) are comparatively rather small, and do not project at all toward
the sides, their pedicle being very short, and the cornea but slightly expanded.

The antennular peduncle (fig. 4) is very powerfully developed, with the two outer
articulations unusually stout and cylindrical in form. The basal joint appears somewhat
flattened, and sends ofi" at the end, above, a broad membranous lobe, overlapping the
base of the second joint. Tl\is lobe, too, is densely hispid above, and furnished at the
inner edge with a row of strong bristles.

The antennal scale (see fig. 5) projects scarcely beyond the second joint of the
antennular peduncle, and is rather broad, oval in form, with the apex evenly rounded off,
and the outer corner unarmed. The basal spine is very narrow, and quite smooth. The
fiagcllum, in all the specimens, was defective, but may no doubt originally have been
very elongate, since the basal part exhibits a most unusually strong and massive
appearance.

The mandibular palp (fig. 6) agrees as to form and relative size wdth that of the
typical species, though much more densely beset with bristles, and has, too, the last
joint somewhat conically pointed.

The first pair of maxilla3 (fig. 7) are in particular distinguished by the remarkably
narrow form of the terminal joint, whereas the masticatory lobes, as also the exoguath,
occur more fully developed than in Thysctnopoda triaisjoidata.

The second pair of maxillae (fig. 8) have the terminal joint unusually large and broad,
as also furnished with nimierous bristles, those springing from the inner edge being very
slender and elongate.

The maxillipeds do not diS"er essentially from those in the preceding species.

The first pair of legs have the last joint (fig. 9) remarkably short and compressed,
almost triangular in form, and, exclusive of the apical setae, furnished at the inner edge
with a dense row of comparatively short ciliate bristles, the anterior of which is recurved.

The succeeding pairs of legs (see fig. 1) are rather slender, and diminisli successively
in length backwards.

The penultimate pair of legs (fig. 10) do not appear much shorter than the one pre-
ceding them, and have the meral joint comparativel}' elongate, as also the terming part
more fully developed than in Tliysanopoda tncuspidata.

Tlie last pair of legs (see fig. 12) do not exhibit, as in the typical species, the
slightest trace of an endopod, whereas the exopod is in every respect normally developed.

The five anterior pairs of gills (see fig. 10) have the exterior branch very small, not
attaining l)y far the size of tlie interior, which is somcMdiat elongate, and furnished along

104 THE VOYAGE OF H.M.S. UHALLENGEK.

both edges with numerous gill-lobules. On the penultimate pair (see fig. 11) the
exterior branch is much more developed, and divided into several curving stems. The
last pair of gills (fig. 12), finally, agree closely in structure with those in the preceding
species, both of the branches being strongly developed, and provided with numerous
secondary stems.

The copulatory appendages to the first two pairs of pleopoda in the male (figs. 13, 14)
exhibit in their general structure very considerable resemblance to those in the genus
Eu2)hausia.

The telson (see fig. 3) is very slender, and tapers gradually posteriorly, with the
apex, however, not nearly so produced as in Tlujsanopoda tricuspidata, but obtusely
lanceolate in form, as also wanting the secondary denticles occurring in that species.
On the upper face of the telson occur two parallel longitudinal keels, distinctly serrate
throughout almost their whole length. The subapical spines are very strong and divergent,
extending far beyond the tip of the telson, and have their inner edge sharpened but quite
smooth.

The uropoda (ihid.) appear scarcely shorter than the telson, and have the outer plate
both broader and longer than the inner.

The colour, according to a sketch, apparently of this species, by Sir. J. D. Hooker, is
light brown. One of the Challenger specimens has here and there partly retained this
tint, the posterior part of the tail, for example, exhibiting numerous dark browTi pigment-
spots (see fig. 1).

Habitat. — The Challenger specimens were collected in the two following localities : —

Date.

Locality. i

1
October U, 1875.

Pacific, one specimen, treated -with carmine.
South Pacific, from tow-net attached to the trawl, two
specimens (one dissected).

The distribution of the species is therefore, so far as yet known, apparently restricted
to the Pacific Ocean.

27. Thiimnopoda cristata, G. 0. Sars (PI. XVIII. figs. 15-20).

Thijsanoijoda cristata, G. O. Sars, Prehminary Notices on the Challenger Schizojjoda, No. 26.

Specific Characters. — Body rather compressed. Carapace without lateral denticles ;
anterior part with a well-marked crest along the middle ; rostral projection rather strong,
cultrate, with a small denticle above near the tip. Caudal epimera comparatively large ;
fourth and fifth segments with a small dorsal spine ; last segment scarcely longer than

REPORT ON THE SCIIIZOPODA. 100

preceding, preaual spine obsolete. Eyes very short. Antcnnular peduncle without
distinct dorsal lappets, but exhibiting an unusually strong seta that issues from inner
corner of last joint. Antennal scale oval in form, with rounded apex and outer corner
jutting out as a well-defined tooth. Telson with six pairs of dorsal denticles, apex but
slightly produced, subapical spines smooth. Inner plate of uropoda shorter than outer.
Length 55 mm.

Remarks. — There cannot, I think, be any doubt whatever as to this form also being a
true Thysanopoda, though the oral parts and gills could not in the single specimen taken
be submitted to a close examination. The species may be readily distinguished from
either of the two preceding ones by its strongly compressed body, elevated dorsal crest,
and peculiar rostrum.

Description. — Only a single specimen of this species, an adult male, was secured. It
has a length of as much as 55 mm., and accordingly ranks among the largest forms of
the Euphausiidfe.

The body (see PI. XVIII. fig. 15) is rather stout, but very much compressed
throughout.

The carapace lacks, as in Thysanopoda ohtusifrons, every trace of lateral denticles,
the inferior margins being quite smooth and evenly incurved along the middle. The
anterior part has a well-marked and somewhat elevated crest in the middle, and juts out
as a distinctly developed rostrum, reaching almost to the end of the basal joint of the
antennulfB. The form of the rostrum is also in this species somewhat ditferent from
that usually met with in the Euphausiidse, being somewhat cultrate, with a sharp carina
both at the upper and the lower side, the former constituting a continuation of the
dorsal crest of the carapace. Its apex is drawn out to a sharp somewhat deflexed point,
and a little behind the latter a very small denticle occurs on the upper edge of the
rostrum.

The caudal segments are very powerfully developed, with rather large epimera of a
slightly irregular form, the three middle ones being, as in Tliysanopoda ohtusifrons,
sinuate along the inferior edge. The three anterior segments are quite smooth above,
whereas the two succeeding ones exhibit a small spiniform projection in the middle of
the posterior margin. The last segment scarcely exceeds in length the preceding, and
does not exhibit any trace of a preanal spine.

The eyes (see figs. 15, 16) are very short, almost globular in form, and [)roject but
little, if at all, beyond the sides.

The antennular peduncle (see fig. 16) is rather strong, with the anterior border of
the basal joint somewhat thickened and densely setose, though not constituting a true
lobe, and the outer corner is produced as a spiniform projection. The second joint
projects above at the end as a small triangular lappet, overlapping the base of the
terminal joint. The latter exhibits at the inner edge, near the tip, a remarkably strong

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) Oo 14

1(»G THE VOYAGE OF H.M.S. CHALLENGER.

forward directed seta, which at the first gUxnce may be taken for a third fiagellum.
The true Haticlla are exceediiiuly elongate, nearly equalling the length of the whole
body.

The antennal scale (see fig. IG), reaching but slightly beyond the second joint of the
antennular peduncle, is rather broad, of an oval form, and obtusely rounded at the tip,
with the outer corner jutting out as a well marked though rather small denticle. The
tlaii;;ellum is very elongate, even slightly exceeding in length those on the antennulse.

The oral parts of course could not be accurately examined in the single specimen
preserved.

The maxillipeds and legs, as also the gills, would not appear to differ essentially from
those parts in Thysanopoda ohtusifrons.

The copulatory appendages to the first pair of pleopoda (fig. 19) are somewhat
.similar to those in the last species. A few minor differences may, however, be found
in the structural details. Thus, lioth the hook-shaped processes of the outer part
axe quite simple, subulate, whereas in Thysanopoda obtusifrons one is slightly dilated
at the tip and the other distinctly angulate at the base. The appendages to the second
pair (fig. "20) agree almost exactly with those in the above mentioned species.

The telson (see fig. 17) is of moderate length, tapering uniformly towards the apex,
which is acutely pointed. The subapical spines (see fig. 18) are comparatively small and
scarcely at all divergent, as also quite smooth. Moreover, on the dorsal face of the telson
may be seen about six pairs of small denticles.

The uropoda (see fig. 17), when extended backward, reach a little beyond the tip
of the telson, and exhibit between the plates a relation similar to that in Thysanopoda
obtusifrons, the inner being appreciably shorter than the outer.

Habitat. — The only specimen secured was brought up in the trawd from a consider-
able depth in the Celebes Sea, south of Mindanao, Philippine Islands — Station 213,
February 8, 1875 ; lat. 5° 47' N., long. 124° 1' E.; depth, 2050 fathoms ; blue mud.

In all probability the specimen in question did not actually enter the trawl at that
enormous depth, but most likely was taken by the net during its upward passage from
some intermediate stratum of the sea.

28. Thysanop)oda microphthalma. n. sp. (Woodcut, Fig. 3).

Specific Characters. — Form of body comparatively slender. Carapace with a single
lateral denticle, projecting from the inferior margin far behind the middle ; anterior p»art
very slightly keeled above, and jutting forth as a well-marked acuminate rostrum. Caudal
segments smooth above, with epimera not very large. Last segment longer than
preceding ; preanal spine distinct unguiform. Eyes exceedingly small, rounded.
Antennular peduncle strong, with a densely hispid lobe projecting from the basal joint

KEPORT ON THE SCHIZOPODA.

lOi

above and drawn ont to a strong spinr. Antennal scale oblong-ovate ; apex rounded, with
no denticle on outer corner. Penultimate pair of legs much shorter than preceding.
Telson wdth numerous small dorsal denticles. Inner plate of uropoda scarcely shorter
than outer. Length 15 mm.

Remarks. — Of this form, not recorded in my Preliminary Notices, the collection
contains a single, apparently young, specimen, stained with carmine and mounted on a
glass slide. It is somewhat defective, wanting, as it does, several of the legs, as also the
outer part of the telson. Quite recently I have, however, had an opportunity of examining
another sjaecimen of the same species, in an excellent state of preservation, brought home
by the Norwegian traveller, Mr. Lumholtz. I have tlius been enaVded to make out the
distinctive characters with greater pi'ecision, and at the same time been fully convinced
that the form in question constitutes a new and well-marked species of the genus

Fig. 3. Tht/sannjjodo jmcroplf/hnlma^ n. sp.

TJiysanopoda. Owing to the species not being figured in the plates, I have subjoined a
woodcut, exhibiting the Challenger specimen from the riglit side. This form is closelv
allied to Thysanopoda ohtusifrons, from which, however, it may be at once distinguished
by the sharply pointed rostrum and the well-marked lateral denticle of the carapace.
Moreover, its specific designation is derived from tlic remarkably small size of the eyes.

Description. — The Challenger specimen has a length of 1 5 mm. That secured by
Mr. Lumholtz, which appears full grown, is considerably larger, measuring about 2-2 mm.
in length. Both specimens are females.

The form of the body (Fig. 3) appears somewhat more slender than in any of the
preceding species.

The carapace has on either side a well-marked lateral denticle, extending from the
inferior margins far behind the middle, or, more precisely, just above the base of the
penultimate pair of legs. Its anterior part is veiy slightly keeled above, and projects

108 THE VOYAGE OF H.M.S. CHALLENGEE.

as a well defined, though rather short, acutely pointed rostrum, somewhat compressed in
its outer part.

The caudal segments in the Challenger specimen would appear to be quite smooth
above, whereas in that obtained by Mr. Lumholtz a distinct, though very small, dentiform
process is seen projecting above from the end of the third segment. The epimera are
of the usual appearance, rather small in the Challenger specimen, a trifle larger in the
other. The last segment is somewhat longer than the preceding, and exhibits at the end,
inferiorly, a well-marked unguiform preanal spine.

The eyes are exceedingly small, more so even than in Thjmnopoda ohtusifrons, and of
a rounded form, with the cornea occupying about the outer half of the eye.

The antennular peduncle is rather strong, and not unlike that of J?i,ijsanopoda ohtusi-
frons in form, having, as in that species, a densely hispid lobe projecting above from the
end of the basal joint. This lobe, however, has in the present species the outer corner
drawn out to a strong spiniform projection, and, moreover, another but much smaller
lobe occurs extending above from the second joint.

The antennal scale would appear to have much the same form as that in Tliysanopoda
ohtusifrons, though perhaps a trifle more oblong.

As regards the oral parts and the gills, no detailed examination could be made, for
want of sufficient material.

The legs present apparently a close resemblance to those in Tliysanopoda ohtusifrons,
.saving, however, that the penultimate pair is relatively somewhat shorter.

As stated above, the outer part of the telson was broken ofi" in the Challenger
specimen. In the other (Mr. Lumholtz's) it is of moderate size, and furnished with about
nine pairs of small dorsal denticles, exclusive of the subapical spines, which arc somewhat
slender and smooth.

The uropoda, when extended posteriorly, reach a little beyond the t\\) of the telson,
and have the inner plate but very little shorter than the outer.

Habitat. — The Challenger specimen was taken at the surface of the sea, in the North
Atlantic, May 3, 1876 ; lat. 26° 21' N., long. 33° 37' W.

The specimen procured by Mr. Lumholtz was likewise obtained with the surface-net,
but in the tropical region of the Atlantic, lat. 7° N., long. 23° W.

The distribution of the species as yet knowTi, would accordingly appear restricted to
the Atlantic Ocean.

Genus. 3. Bentheuphausia, n. gen.

Generic Characters. — Body scarcely compressed. Eyes imperfectly developed.
Flagella of both pairs of antennae greatly elongate. Antennular peduncle remarkably
short and stout. Oral parts very peculiar in structure. Mandibles strongly develoi^ed,

REPORT ON THE SCHIZOPODA. 10{»

with greatly expanded masticatory part, cutting edge but sliglith- dentate ; palp very
large. First pair of maxillte with anterior masticatory lobe strongly projecting and conrscly
spinous along the edge ; palp small but distinctly tri-articulate ; exognath drawn out
posteriorly as a narrow lappet. Second pair of maxilla? with a prodigiously developed
palp, consisting of three distinctly defined lamellar articulations. Maxillipods rather
strong, pediform. All of the legs distinctly developed, with the joints more or less lamellar,
expanded ; last pair rather short, but having both endopod and exopod well defined and
of a structure similar to that in the preceding pairs. Gills very fully developed, the
three posterior pairs exceedingly complex ; last pair by for the largest. Telson compara-
tively short. Uropoda with the plates remarkably broad, outer one distinctly jointed
near the apex. Luminous globules apparently wanting.

Remarks. — This genus I have seen fit to estabhsh for the reception of the anomalous
form recorded by myself at an earlier date as Thysanopoda amhlyops, and first examined
from a defective specimen only. Having since found in the collection another somewhat
broken specimen, I had the means of making a more detailed anatomical investigation
and thus became convinced, that the form in question constitutes the type of a specially
distinct and very peculiar genus. More particularly the oral parts exhibit a most
remarkable structure, totally different from that in any other known genus of Euphau-
sidians. Moreover, the gills present certain well-marked peculiarities of structitre ; and
finally, the genus is the only one in which all the legs, even the last pair, are full}-
developed. The imperfect development of the eyes would seem to support the assumption
of the present form being a true deep-sea animal ; and hence I have deemed it advisable
to designate the genus accordingly.

29. Bentheupliausia amhlyops, G. 0. Sars. (PI. XIX., Woodcut, Fig. 4).

Thysanopoda (?) amhlyops, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 27.

Specific Characters. — Body almost cylindrical in form. Carapace without any lateral
denticles, anterior part very slightly keeled above, with frontal margin produced in the
middle into an acute angle. Caudal segments smooth above, with rather small, rounded
epimera. Last segment somewhat longer than preceding, preanal spine obsolete. Eyes
very small, with pedicle narrow, cylindrical, and slightly expanded at the cud above, cornea
exceedingly minute, with light pigment and imperfectlj^ developed visual elements.
Antennular peduncle short and thick, somewhat flattened at base, with an acute lobe
projecting from basal joint above. Antennal scale almost reaching extremity of
antennular peduncle, oblong-ovate in form, apex obliquely rounded, outer corner scarcely
at all projecting. Telson flattened, tapering, with two pairs of small dorsal denticles ;
apex pointed, subapical spines smooth. Uropoda scarcely, if at all, longer than telson,

110

THE VOYAGE OF H.M.S. CHALLENGEK.

with eiutor plates the larger, aud exhibiting exteriorly a small tooth somewhat remote
from the apex. Length reaching 48 mm.

Remarks. — Among the drawings executed during the expedition by the late Dr. v.
Willemoes-Suhm, there is one that undoubtedly represents this species, aud as the specimen
from wdiich the drawing was executed, according to the subjoined notes, must have been
very considerably larger than the ones examined by myself, and had, too, all its legs
uninjured, I have seen fit to reproduce the figure in the annexed cut. In his manuscript
notes, the late lamented naturalist has only recorded this interesting form as Thysano-
2)oda sp. ? — Unfortunately, the specimen has been lost, and hence the following descrip-
tion has been worked out in all essential particulars from the smaller ones, examined by
myself.

Description. — The length of the specimen represented in PI. XIX. fig. 1, is 20 mm.,

»-

Fig. 4. Benthiuphaiisia amUyopx, G. 0. Sari!, n. gen.

and that selected for anatomical investigation had very nearly the same size. Thi-
specimen examined by the late Dr. v. Willemoes-Suhm, and figured in the accompanpng
cut, was much larger, measuring, as stated by that author, not less than 48 mm. in length.
All|^three specimens were fem;iles.

The form of the body (see PI. XIX. fig. 1, and accompanying cut) is somewhat
slender, and diff"ers from that in most other Euphausiidaj in being very little, if at all,
compressed, but nearly cylindrical throughout.

The carapace has not a trace of lateral denticles, the inferior margins being quite
smooth and almost straight. The anterior part is defined posteriorly by a slight cervical
impression, and exhibits above, in the middle, a low keel, obsolete anteriorly. The
frontal margin projects in the middle as an acute angle extending above the bases of the
eyes, \vithout, however, forming any true rostrum. The antero-lateral corners of the
carapace are obtusely truncate. Posteriorly, the carapace forms a deep and narrow emargi-
nation, leaving, as usual, the dorsal part of the last segment of the trunk uncovered.

REPORT ON THE SCHIZOPODA. HI

The caudal .sogments are quite smooth above, and provided with comparatively rather
small, rounded epiniera. The last segment somewhat exceeds in length the jjreceding,
cind does not exhibit any trace of a preanal spine.

The eyes (see figs. 2 and 4) are remarkably small, incompletely developed, and do not
in the least project beyond the sides of the carapace. The jjcdicle is narrow cylindrical,
but expands at the end, above, as a knob-like prominence. The cornea occujiies only a
small part of the eye, and is distinguished by its light, whitish pigment, as also by the
surface exhibiting no true corneal facets or other visual elements, bvit merely an
indistinct and irregular areolation.

The antennular peduncle (figs. 5, G) is remarkaljl\- slmrt and thick, with the basal
joint somewhat flattened, and ab(jut as large as the other two taken together ; moreover,
it juts out above at the end, somewhat interiorly, as a pointed process, bearing on the
inner edge a row of stiiF incurved bristles (see fig. 6). The fiagella were broken off" in the
specimens examined, but would seem to have been rather elongate, judging from the
thickness of the still remaining basal part, more especially of the outer flagellum.

The antenna! scale (fig. 7) about ecpials in length the antennular jjeduncle, and exhibits
an oblong-ovate form, the apex being broadly rounded and somewhat oblique, with the
outer corner not in the least projecting, and armed with a very minute denticle. The
basal spine is likewise very small, nearly obsolete, whereas the peduncle of the flagellum
is very strong, reaching to the tip of the scale. The terminal part of the flagellum was
broken off" in the specimens examined, but may no doubt have been very elongate.

The anterior lip (fig. 8) is comparatively large, and has the lateral corners a good
deal projecting; for the rest, it shows the stucture characteristic of the family.

This will also apply to the posterior lip (fig. 9), the terminal lobes of which have the
usual triangular form.

The mandibles (figs. 10, II) are very strong, with the masticatory part considerably
expanded, securiform, and scooped out a little anteriorly. The cutting edge is sharpened
and exhibits a small number only of scattered teeth, somewhat differently arranged on
the two mandibles (see fig. 10). The palp is comparatively very large, fully equalling the
mandible itself in length. Of its joints, the middle one is by far the largest, and rather
broad, as also fringed along both edges with strong ciliated bristles. The last joint is
oblong, and furnished along the inner edge with a double series of bristles.

The maxilla} (figs. 12, 13) exhibit a structure very different from that observed in
any hitherto known form of Euphausiidas, and would thus fully warrant the generic
distinctness of the present form.

The first pair of maxillae (fig. 12) have the two masticatory lobes very unequally
developed, the posterior lo'oe forming merely a broad, lamellar expansion of the basal
part, fringed along the edge with a dense row of plumose setae, whereas the anterior lobe
projects very considerably, and is dilated into a somewhat securiform apex, which is

112 THE VOYAGE OF H.M.S. CHALLENGER.

armeil along the edge -witli a rather hirge numbei" of strong spines, unequal in size.
The i)alp, unlike that of other Euphausiidse, is distinctly triarticulate, though ver)^
small, the middle joint being the largest, and furnished along the inner edge with a row
of strong bristles, whereas the basal and terminal joints are quite unarmed. The
exognath, finally, constitutes an oval plate, without any bristles, and of a peculiar almost
spongy structure. Moreover, it is specially distinguished by the posterior part being
drawn out into a narrow, finely ciliate, lobe.

The second pair of maxilte (fig. 13) exhibit a perhaps still more anomalous aspect,
owing to the prodigious development of the palp. The latter, constituting, as it does, in
all other known Euphausiid^e, only a single lamellar joint, occurs here as a large trunk,
fidly equal in length to the remaining part of the maxilla, and composed of three well-
defined lamellar expanded articulations, giving to the maxilla, as it were, a pediform
appearance. Of the joints, the first is by far the largest and very broad, oval in form,
and fringed along the inner edge with numerous long curving plumose setae. The two
outer joints rapidl)' diminish in size, and are likewise j^i'ovided with strong plumose setse
along the inner edge, as also a few much shorter ones at the outer. The remaining part
of the maxilla exhibits, on the whole, a normal appearance, having interiorly four densely
setose masticatory lobes, and exteriorly a small lamellar exognath edged with short
ciliate bristles.

The maxillipeds (fig. 14) exhibit the usual pediform structure, having, however, the
proximal part remarkably robust, -n-ith the joints much ajipressed, whereas the distal part,
consisting of the outer three joints, would seem to Ije somewhat slender and very movably
jointed to the former. The meral joint, by far the largest, slightly exceeds in length the
distal part. All the joints are provided along the inner edge with a number of slender
scattered bristles. The masticatory lobe, issuing internally from the coxal joint, is found
on closer examination (see fig. 15) to consist of two superposed lappets, both edged with
strong curving set«. The exopodite is rather powerfully developed, reaching beyond
the middle of the meral joint. The epipodite, finally, constitutes a small membranous
plate, projecting both anteriorly and posteriorly as a rounded lobe.

All the legs, save the last pair, had been broken oS" in the specimens I examined, only
their basal parts along with the gills and exopods being left. In the specimen, however,
examined by the late Dr. v. Willemoes-Suhm, they had suffered no mutilation and were
fully represented in the figure drawn by that naturalist, of which the annexed cut is an
accurate copy. As seen from the figure, they are rather elongate, but relatively coarser
in structure, than in other Euphausiidse, the joints being much appressed and densely
setose.

The last pair of legs (fig. 18) are much smaller than the rest, and in the specimens
examined were almost entirely hidden between the gills, so as readily to escape attention.
Hence, too, they came to be quite overlooked by myself as also by the late Dr. v.

REPORT ON THE SCHIZOPODA. 113

Willemoes-Suhm, who simply states in his manuscript notes, that they occurred as a
mere rudiment. On dissecting one of the specimens in the collection, I found them,
however, developed precisely as the rest, both the exopod and cndopod being well defined,
the latter as a distinctly articulate stem, differing merely in haviug the terminal part
very small and composed of only two articulations.

The gills (see figs. 16-24), although on the whole presenting the structure and
arrangement characteristic of the family, yet exhibit certain striking peculiarities. They
increase successively in size posteriorly, and become, as they do so, more complex in
structure, the three hindmost pairs being richly arborescent. In no other form of
Euphausiidse does the homology of the gills to the epipod admit of being better
demonstrated than in the present animal. For in the anterior pair (see figs. 16 and 19)
the epipod-plate retains precisely the original aspect it has in the maxillipeds, whereas
the true branchial part is found to be merely an out-growth from the exterior face of this
plate, in the form of a curved stem fringed along its posterior edge with a regular series
of gill-lobules of the usual structure. In the second pair (fig. 20) the interior extremity
of the epipod-plate has become somewhat produced, and from its apex a single minute
gill-lobule has taken origin, whereas the outer gill-stem remains unaltered. In the third
pair (fig. 21) the inner part of the epipod-plate has taken a still more striking gill-like
aspect, several other gill-lobules having made their appearance on its edge ; and in the
following pair, this would appear characteristic to a still greater extent. Finall}', in the fifth
and sixth paii's (figs. 22, 23), the inner part of the epipod-plate has been so greatly
modified as to assume the aspect of the principal part of the gill, furnished, as it is, with
several spirally arranged gill-stems, each subdivided into numerous lobules. Yet in aU
those pairs, the outer part of the epij)od-plate has remained almost unchanged, forming a
simple rounded lobe, of a peculiar, as it were spongy structure, and projecting above the
true gills (see fig. 1). The last pair of gills (see figs. 18-24) are very large, and, as usual,
exhibit two principal diametrically diverging sections, both of which are divided into
numerous secondary branches, partly spiral in arrangement, and all of them furnished at
one of their edges with a regular series of gill-lobules.

The pleopoda (fig. 25) do not exhibit any marked peculiarities of structure.

The telson (see fig. 3) is relatively less produced than in other Euphausidians, and
scarcely longer than the last segment. Moreover, it is somewhat flattened throughout,
tapering gradually toward the apex, which is sharply pointed. The subapical spines are
rather slender, reaching far beyond the tip of the telson, and perfectly smooth. On the
dorsal face of the telson occur in addition two pairs of very small denticles.

The uropoda (ibid.) scarcely extend beyond the telson, and have both plates compara-
tively br(.iad and lamellar. The inner plate, which is the shorter, is lanceolate and
fringed all round with plumose setae. The outer plate is oblong in form, and exhibits,
contrary to what is the case in other Eupliausiidae, in its outer part a distinct

(ZOOL. CHALL. EXP. PART XXXVH. — 1885.) Oo 15

11-1: THE VOYAGE OF H.M.S. CHALLENGER.

transverse suture, marking oflf a linguiform terminal joint, as in Gnathophausia or
Eucopia ; its outer edge is quite straight and naked, terminating in a small dentiform
projection, whence the above mentioned suture runs inward.

Of luminous globules I failed on dissection to detect any trace whatever. True, the
late Dr. v. Willemoes-Suhm observes in his manuscript notes having indistinctly been
able to trace a number of accessory eyes (Nebenaugen) on the anterior division of tlie l;)ody,
.•111(1 lias also represented such organs in his drawing (see woodcut, fig. 4, p. 110) as occur-
ring at the bases of all the legs. But, to judge from the place assigned, I feel convinced
tliat he has obviously taken for accessory eyes the iucrassated outer lobe of the epipod-
plates, these, perhaps, being more vividly coloured than the rest.

Colour. — According to the manuscript notes of the late Dr. v. Willemoes-Suhm, the
whole body of the animal in a fresh state, unlike what occurs in other Euphausiidse, is
quite opaque and of a similar vivid-red colour to that in most other true deep-sea
Crustaceans.

Habitat. — The two sjiecimens examined by myself were taken in the following
localities: —

October 1873, off Tristan da Cunha ; depth, 1000 fathoms.

Station 107, August 26, 1873, Tropical Atlantic; lat. 1° 22' N., long. 26° 36' W. ;
depth, 1500 fathoms ; Globigerina ooze; bottom temperature, 37° "9.

The specimen examined by the late Dr. v. Willemoes-Suhm was obtained south of
Australia, in the following locality : —

Station 158, March 7, 1874; lat. 50° 1' S., long. 123° 4' E.; depth, 1800 fathoms;
Globigerina ooze ; bottom temperature, 33° "5.

As regards distribution, this form, therefore, would appear to inhabit the abysses of
the Atlantic and Southern Oceans.

Genus 4. Nyctiphanes, G. 0. Sars, 1883.

Nydiphanns, G. 0. Sars, Prelimiiiary Notices ou the Challenger Shizopoda.

Generic Characters. — General appearance as in Euphatisia. Flagella of both pairs of
antennae greatly elongate. Antennular peduncle elongate, cylindrical, stronger in male
than in female, basal joint provided above at extremity with a re flexed membranous
leaflet. Oral parts and anterior legs very nearly as in Euphausia. Penultimate pair of
legs distinctly developed, but differing from the rest in the endopod consisting of two
elongate joints only. Last pair of legs quite rudimentary, forming a minute non-
articulate and flexuose stem, without any bristles. Last pair of gills rather complex,
remaining pairs comparatively simple, main stem expanded at extremity and drawn out
as two diverging points. Ovisac double. Luminous globules as in Euphausia.

Mernarks. — This genus is mainly characterised by the peculiar reflexed leaflet on the

REPORT ON THE SCHIZOPODA. 115

antenmilar peduncle, as also by the structure of the two hindmost pairs of legs, both of
which are rather dissimilar, as compared with those in other Euphausiidfc. Moreover, the
structure of the gills is somewhat different. Finally, the genus is highly distinguished
by the presence in the female of a double ovisac. Besides the new species described
below, the northern form, Thysanopoda norvegica, M. Sars, which, perhaps, is identical
with Thysanopoda couchii of Bell, belongs to this genus. The generic name proposed
here is a translation into Greek of the appellation "Noctiluca," adapted 1)y AY. Thompson
for a form of this family, but preoccupied in zoology for a Protozoon.

30. Nyctiphanes australis, G. 0. Sars (PI. XX.; PI. XXI. figs. 1-7).

Nydiphanes audralis, G. 0. Sar.s, Preliminary iSTotices on tlie Challenger Schizopoda, No. 28.

Specific Characters. — Form of body rather slender. Carapace without any lateral
denticles, anterior part distinctly keeled above; rostral projection very short; frontal
margin forming on either side, above the eyes, an obtuse angle. The two anterior caudal
segments having the posterior margin slightly produced in the middle ; epimera of
moderate size, subtriangular, pointing obliquely backward. Last segment not longer than
preceding ; preanal spine obsolete. Eyes large and protruding, pyriform. Antennular
peduncle very elongate, outer corner of basal joint drawn out to a sharp spine, dorsal
leaflet comparatively small, with inner corner acute, outer edge entire. Antenna! scale
not nearly reaching the tip of second joint of antennular peduncle, narrow, .sublinear,
outer corner produced as a well-marked tooth. Mandibular palp remarkably elongate.
Legs very slender, antepenultimate and penultimate pairs in female wanting exopod. Last
joint of penultimate pair half as long as preceding joint. Penultimate pair of gills without
secondary branch. Telson "with obtusely lanceolate apex ; subapical spines slender and
smooth. Inner plate of uropoda a trifle longer than outer, and reaching tip of telsou.
Ovisacs conoid, afiixed in part to antepenultimate paii' of legs. Length reaching 17 mm.

Remarks. — From the northern form, Nyctiphanes norvegica (M. Sars), this species is
easily distinguished by its more slender form, the absence of lateral denticles on the
carapace, the much more elongate antennular peduncle, the form of the doi-sal leaflet
thereon, and, finally, by a somewhat difi"erent relation in size between the two joints of the
endopod of the penultimate pair of legs. Moreover, the structure of the gills and the
form and arrangement of the ovisacs would seem to be somewhat diff"ereut in the two
species.

Description. — The length of the adult male is about 17 mm., that of the female
somewhat less.

The form of the body in both sexes (see PI. XX. fig. 1 ; PI. XXI. fig. 1) is rather slender,
but somewhat different as regards the relation in size between the anterior and posterior
divisions, the latter being more fully developed in the male (see PI. XXL fig. 1), and

110 THE VOYAGE OF H.M.S. CHALLENGER.

about twice as long as the former, whereas in the female (PL XX. fig. l) the difference in
h-nsith between the two divisions is much less.

The carapace lacks every trace of lateral denticles, the inferior margins being quite
smooth and nearly straight. The anterior part is marked off posteriorly by a slight
cervical impression, and exhibits above a distinct, though somewhat low keel. The
frontal margin juts out in the middle (see PI. XX. fig. .3 ; PI. XXI. fig. 2) as a compara-
tively short triangular projection, reaching but very little beyond the ocular segment,
forming, too, on either side, above the eyes, an obtuse angle. The antero-lateral corners of
the carapace constitute a distinctly projecting angle. Posteriorly, the carapace exhibits
a rather deep emargination (see PI. XXI. fig. 3), from which juts on either side a narrow
sinus, disrupting the hinder margin.

The caudal segments are all nearly uniform in length, but diminish hindwards succes-
sively both in breadth and height. The two foremost have the posterior margin very
slightly produced above in the middle, but, in other respects, these segments are quite
smooth above. The epimera are of moderate size and somewhat triangular in form,
pointing obliquely backward and terminating in an acute angle. The last segment is
relatively very short, its length not exceeding that of the preceding, and wants the
slighest trace of a preanal spine.

The eyes (see PI. XX. fig. 2 ; PI. XXI. fig. 2) are very large, projecting towards either
side, pyriform, with the cornea greatly expanded.

The antennular peduncle is somewhat different in the two sexes. In the female
(PI. XX. figs. 4-6) it is exceedingly slender, and scarcely exceeds half the length of
the carapace, whereas in the male (see PL XXI. figs. 1, 2) it is much more powerfully
developed, attaining almost the whole length of the carapace. The basal joint is somewhat
flattened, and projects at the outer corner as a sharp tooth. The dorsal leaflet, springing,
above, from the end of this joint, is reflexed, as in the northern species, but compara-
tively more simple in structure, having only the inner corner acutely produced, whereas
the edges are evenly curved and quite smooth. The second joint is very elongate,
attaining almost the length of the basal joint, and, in the female, very narrow and
perfectly cylindrical in form, whereas in the male (see PL XXL fig. 2) it is much thicker,
and exhibits at the inner edge, near the apex, an obtuse prominence that lies in close
contact with the corresponding prominence on the opposite side, when the peduncles are
extended in their normal position. The last joint is only half as large as the former, and
in the male remarkably dilated and somewhat curved. The flagella are very elongate,
and composed of numerous short articulations.

The antennal scale (see PL XX. fig. 7) is comparatively small, not nearly reaching
the end of the second joint of the antennular peduncle, and exhibits a rather narrow,
nearly linear form, tapering slightly, however, toward the apex, which is narrowly
truncate, with the outer corner produced as a well-defined tooth. The basal spine is very

REPORT ON THE SCHIZOPODA. 117

small and quite smooth. Tlie basal part of the flagellum is rather elongate, in the female
about equalling the length of the scale, in the male {see PI. XXI. fig. 4) considerably
projecting beyond its apex, and having the last joint remarkably large and tumid.

The anterior and posterior lips (PI. XX. figs. 8, 9) do not exhibit any marked
peculiarities of structure.

The mandibles (fig. 10) are comparatively powerful, with the cutting edge (see fig. 1 1)
divided, as usual, into several sharp teeth, and exhibiting besides a well-marked molar
protuberance. The palp (see fig. 10) is remarkably slender and elongate, exceeding even
the body of the maudiljle in length, and has the terminal joint nearly as long as the
medial, as also somewhat expanded towards the tip, and armed along the inner edge with
a row of ciliated bristles, which at the apex assume the character of strong curved spines.

The first pair of maxillae (fig. 12) have the terminal joint, or palp, rather small and
narrow, whereas the exognath is very large and oval in form, witli only a pair of minute
Ijristles at the anterior extremity.

The second pair of maxillse (fig. 1 3) exhibit the usual structure, with the terminal
joint approximately triangular in shape.

The maxillipeds (fig. 14) occur, as usual, quite pediform and very slender, with the
terminal joint (fig. 14a) linear and furnished along the inner edge with a row of small
ciliated bristles, besides a few longer setae. The epipodite forms a very small, narrow,
triangular lamella, afiixed to the outer side of the coxal joint.

The legs (see Pis. XX., XXI. fig. 1) are exceedingly slender and elongate, as also
densely setose, with the ischial joint longest. They increase somewhat in length as far as
the third pair, where they gradually diminish a little in size. On the first pair (fig. 15)
the terminal joint occurs but very slightly expanded, haAdng, however, the usual bunch of
ciliated bristles near the tip (see fig. 15«). In this pair, as in the three succeeding (see
fig. 16), the terminal part, consisting of the three outer articulations, is much longer than
the meral joint, whereas in the antepenultimate pair (fig. 17) this part is much reduced in
size. On the other hand, in this pair the ischial joint is very elongate, being twice as
long as the meral. The penultimate pair of legs (fig. 18) occur entirely without the
terminal part, the endopod being composed of only two joints, the last of which (meral)
scarcely attains half the length of the preceding. On Iwtli of the last mentioned pairs
the exopod is wholly wanting in the female, whereas in the male this part occurs
distinctly developed (see PI. XXI. fig. 5). The last pair of legs (PI. XX. figs. 19, 20) are
quite rudimentary, being in greater part completely hidden between the posterior gills ;
they constitute a small, somewhat flexuose naked stem springing from a somewhat
thickened basal part, and exhibiting an exceedingly soft consistence, similar to that of
the gill-stems.

The gills increase, as usual, successively in size from before backwards, forming a
regular series along the sides of the trunk below the carapace. The six anterior pairs

118 THE VOYAGE OF H.M.S. CHALLENGER.

(see figs. 15-18) are comparatively simple in structure, and perfectly similar in appear-
ance, occurring as single stems expanded at the extremity into 'two short diverging
corners, and ha\nng along the hinder edge a regular series of digitiform gill-lobules,
diminishing in length towards each extremity. The last pair (fig. 19), on the other hand,
are very large and complex, divided as usual into two principal portions pointing in
opposite directions, the posterior of which is the larger,.and provided with several curved
secondary branches, each having along one of its edges a regular series of gill-lobules.
The pleopoda of the female (fig. 21) do not exhibit any essential peculiarities of structure.
The copulatory appendages to the two first pairs of pleopoda in the male (see PL XXI.
fio'S. 6, 7) are, on the whole, not so fully devcluped as in most other Euphausiidse. Those
on the first pair (fig. 6) form a somewhat curved lamella, doubling over the inner
plate of the pleopod, and with the inner edge finely serrate. From this lamella, also,
proceed tw-o comparatively small processes, the outer of which is mucroniform and highly
chitinised, whereas the inner is narrow liuguiform, and quite soft. Moreover, a slender
incurved spine is seen to spring from a rounded prominence on the outer margin. The
appendages of the second pair of pleopoda (fig. 7) constitute merely a slight two-lobed
expansion of the inner edge of the principal plate.

The telson (see PI. XX. fig. 22) exhibits the usual slender form, tapering gradually
toward the apex, which is but slightly produced and bluntly lanceolate (see fig. 23). The
subapical spines are of moderate length and perfectly smooth. Moreover, two pairs of
small denticles occur on the dorsal face of the telson.

The uropoda (see fig. 22) have the inner plate very narrow and a trifle longer than
the outer, reaching, when extended posteriorly, to the tip of the telson. The outer plate
of each is rather broader, and truncate at the apex, with the outer corner projecting as an
acute angle.

Of the female specimens in the collection, two are ovigerous, a condition very rarely
met with among preserved specimens of Euphausiidse. The eggs were deposited in two
well-defined ovisacs (see PL XX. figs. 1, 2) placed side by side beneath the posterior
part of the trunk. These ovisacs do not consist of incubatory lamellae, as in other
Schizopoda, but merely of an exceedingly thin membrane, derived, it would seem, from
some glutinous fluid issuing along with the ova and coagulated by the action of the sea-
water as a delicate envelope surrounding and keeping the ova together during the
embryonal development. In form, the ovisacs are somewhat conical, being broadest
posteriorly and gradually tapering forward, w^here they are connate with the inner half of
the ischial joint of the antepenultimate pair of legs, covering too, exteriorly, a
considerable part of the succeeding pair. This peculiar arrangement of the ovisacs fuUy
suffices, it would seem, to account for a striking anomaly met with in the present species
and mentioned above, viz., the total absence of exopods on the posterior pairs of legs in
the females. It is, indeed, evident that these organs would be quite inoperative, and

REPORT ON THE SCHIZOPODA. 119

even actually burdensome to ovigerous animals, as the ovisacs would to a very consider-
able extent interfere* with tlicir free mobilit}^ ; hence their develojiment in the females is
quite arrested in that region, whereas in the male they are retained, as usual, on all
the legs, except the last (see PI. XXI. figs. 1,5). Of the northern species, Nyctii'ihanes
couchii, Bell ( = Nyctiphanes norvegica, M. Sars ?), an ovigerous specimen has on one
occasion oidy been observed, viz., by Professor Bell, in whose well-known work on the
British Stalk-eyed Crustacea, the ovisacs are recorded and figured as two rotund sacs
depending freely from the posterior part of the trunk. The form and arrangement of the
ovisacs in the two species accordingly exhibit well-marked differences, though agreeing
in their being not confluent, as is the case in other forms of Euphausidians.

As regards the luminous apparatus, the number and arrangement of the globules
perfectly agrees with that described above in the genus Euphcmsia.

Habitat. — Of the present species rather numerous specimens, besides some few larvae
in a very early stage of development, to be described further on, ^\-ere collected in three
difi'erent localities off the Australian coast. All the specimens were taken in the surface-
net, and in most instances at night. The localities were as follows : —

Date.

Locality.

April 2, 1874.
April 3, 1874.
June 8, 1874.

Off East MonccBur Island, Bass Strait.

Off Cape Howe, south-eastern coast of Australia.

Off Port Jackson, east coast of Australia.

With respect to distribution, the species would accordingly appear to be wholly
confined within the limits of the Australian Seas.

Genus 5. Thysanoessa, Brandt, 18.51.
Thysanoessa, IJrunlt, Middendorf's sibirische Reise, Zoologie.

Generic Characters. — Body more or less slender, tapering posteriorly. Cai-apace short,
distinctly rostrate, antero-lateral corners produced. Eyes of somewhat irregular form,
cornea divided, as it were, into two segments by a transverse constriction. Flagella of
both pairs of antennae very short. Antennular peduncle without any dorsal leaflet,
basal joint much flattened, the two other narrow and elongate. Terminal joint of
second pair of maxillae comparatively small, exognaths in both pairs well developed.
Maxillipeds slender, not very elongate. First pair of legs very strongly developed, and
much longer than the rest, geniculate, meral and cai-pal joints very elongate and nearly
naked, propodal joint compressed, and provided on both edges with strong, spiniform

120 THE VOYAGE OF H.M.S. CHALLENGER.

liristlcs, t(M-niiiial joint very small and spinous. Eemaining pairs of legs successively
diminishing in size. Penultimate pair of legs exceedingly small, endopod bi-articulate,
exopod distinct. Last pair of legs quite rudimentary, forming only a small liuguiform
and setose plate. The three posterior pairs of gills sending off a branch inwards ; exterior
branch in all as in Nyctiphanes. Luminous apparatus of the usual structure.

Remarks. — This genus was established by Brandt for the reception of an Arctic species
from the Siberian Sea, Thysanoessa loiKjipes. I have recorded' two species from the
Norwegian coast, Thysanoessa horealis and Thymnoessa tenera, and in the Challenger
collection there are two other species described below. Thus the genus comprises at
present five different species. They all agree in the characters stated above, the most
striking of which is the strong development of the first pair of legs.

The two Challenger species may be briefly characterised in the following manner : —

Loily

comparatively clumsy, with last segment only slightly longer than preceding.
Rostrum narrow, lanceolate. First pair of legs exceeding half the length of
body. Eyes remarkably large, . . . . . . T. gm/an'a, n. sp.

very slender, with last segment exceedingly elongate and narrow. Rostrum
triangidar, broad at base. First pair of legs not nearly attaining half tlie
length of body. Eyes of moderate size, . . . . . T. macruni, n. sp.

31. Thysanoessa gregaria, G. 0. Sars (PL XXL figs. 8-17 ; PI. XXIL).

Tlujsanoessa gregaria, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 29.

Specific Characters. — Form of body rather short and clumsy. Carapace with a well-
marked lateral denticle behind the middle of the inferior margin ; rostrum produced,
straight, narrow lanceolate. Caudal segments smooth above, with slightly angular epimera.
Last segment somewhat longer than preceding, preanal spine very large, forming a broad
plate, serrate at posterior edge. Eyes remarkal^ly large, irregularly globose, upper part
of cornea narrowed. Antenna! scale reaching beyond second joint of anteunular peduncle,
oblong, tapering, apex obliquely rounded, with outer corner projecting. First pair of
legs, when extended, exceeding half the length of body, meral joint reaching tip of
antennular peduncle. Telson with two pairs of dorsal denticles, apex acuminate ; sub-
apical spines smooth. Inner plate of uropoda a trifle longer than outer, scarcely
reaching tip of telson. Length 1 8 mm.

Rema7']cs. — This species may at once be distinguished from the three northern forms
by its relatively short and clumsy body, as also its remarkabl)^ large eyes. Moreover,
the peculiar form and strong development of the preanal spine would seem to afibrd a
good specifit; character.

Description. — The average length of adult females is about 18 mm. The males are,
as a rule, somewhat smaller.

1 Oversigt over Norges Crustaceer, Bd. i., pp. 52, 5.3, 1882.

REPORT OX THE SCHIZOPODA. 121

The form of the body (see PL XXI. figs. 8, 9) n]>pears rather short and clumsy, and
slightly compressed. It tapers gradually from Ijcfore Ijackwards, and has the tail about
twice the length of the anterior division.

The carapace is comparatively short, and exhibits on either side a weU-marked lateral
denticle jutting out from the lower margins somewhat posterior to the middle, or rather,
just above the insertion of the antepenultimate pair of legs. Its anterior part is defined
posteriorly by a slight cervical impression, and exhibits above a distinct, tliough not very
elevated, keel, continued along the upper face of the rostral projection. The latter (see
fig. 12) is rather produced, reaching considerably beyond the middle of the basal joint of
the autennula3, and has a narrow lanceolate form, being somewhat appresscd at the sides.
In the male this projection (see fig. 17) exhibits a somewhat different aspect, being
remarkably constricted at the base and slightly expanded at the apex, which is bluntly
lanceolate. The antero-lateral corners of the carapace (see fig. 8) are drawn out to a
rather j)rominent acute-angled lobe, overlapping externally the basal part of the antennae.
The posterior emargination of the carapace is not very deep, and without any lateral
sinus.

The caudal segments are quite smooth above, and diminish successively in height
posteriorly. The epimera are well developed, and of a somewhat angular form, pointing
obliquely backwards. The last segment is a trifle longer than the preceding, and some-
what narrow. The preanal spine (fig. 16) exhibits a rather characteristic appearance,
being very broad, lamellar, and with coarse denticles, arranged in a pectinate manner,
along the posterior edge.

The -eyes (see figs. 10, 11) are very large and thick, irregularly globose, with the
pedicle very short, and the cornea greatly expanded. The latter is, as in other species of
the genus, somewhat contracted in its upper part, and divided, as it were, into two
unequal sections by a slight transverse impression, crossing the cornea, a little aliove the
mesial part.

The antennular peduncle (figs. 13, 14) is rather slender, and scarcely exceeds in length
half the carapace. The basal joint is about as long as the two others taken together, and
very much flattened, with the anterior border somewhat projecting above and densely
setose, as also exhil)itiug, at some distance from the inner corner, a narrow indentation.
Its outer corner is drawn out to a dentiform projection, and a little below the inner, two
strono- plumose setae are seen to originate. The two outer joints are very narrow, and
cylindrical in form, the last a trifle longer than the other. The flagella (see fig. 12) are
both exceedingly short, scarcely half as long as the peduncle, and composed of ten to
twelve short articulations.

The antennal scale (see fig. 15) is comparatively large, reaching tar beyond the
second joint of the antennular peduncle. It exhibits a somewhat oblong form, and
tapers gradually toward the apex, which is very oblicjuely rounded, with the outer

(ZOOL. CHAIX. EXP. PART XXXVII. — 1885.) Oo 16

122 THE VOYAGE OF H.M.S. CHALLENGER.

comer somewhat projecting, the inner obsolete. The basal spine is comparatively small,
and quite smooth. The basal part of the flagellum almost equals the scale in length,
and is very slender, with the middle joint longest ; the terminal part does not attain the
length of the basal, and consists of only eight articulations.

The anterior hp (PI. XXII. fig. 1) exhibits the usual structure.

The posterior lip (fig. 2) has the terminal lobes of a somewhat rounded form, with a
small ledge-like projection at the outer edge.

The mandibles (fig. 3) are rather strong, their masticatory part expanded in the
usual manner, the cutting edge (see fig. 5) divided into several acute teeth, and forming
also a well-defined molar tubercle. The palp (see figs. 3, 4) is comparatively small, not
nearly attaining the length of the body of the mandible, and has the terminal joint
lamelliform, as also provided along the inner edge with a dense row of ciliated bristles,
the outermost of which has the character of a strong spine.

The first pair of maxilla (fig. 6) present on the whole a normal appearance, having,
however, the exognath somewhat large and expanded.

The second pair of maxillse (fig. 7) are mainly characterised by the small size and
triangular shape of the terminal joint, or palp. The exognath, too, appears more fully
developed than in any of the preceding genera, constituting, as it does, a distinctly
projecting triangular plate, drawn out anteriorly to a very acute angle, and fringed along
the outer edge with a dense row of plumose setse.

The maxillipeds (fig. 8) are exceedingly slender, though not particularly elongate,
scarcely reaching, when extended anteriorly, beyond the antenna! scale. Of the joints, the
meral is by far the longest, exceeding even in length the three outer ones taken together.
The terminal joint (see fig. 9) is relatively very small, and j)rovided with several slender
bristles, two of which issue from a ledge-like prominence at the outer edge. The
exopodite is remarkably elongated, reaching nearly to the tip of the meral joint, and in
size appreciably exceeds the true exopods on the legs. The epipodite, on the other hand,
is very small and lobular.

The first pair of legs (fig. 10) are most powerfully developed, and much larger than
any of the others, exceeding, as they do, when fully extended, half the length of the
whole body. As a rule they exhibit, however, a strong geniculate bend, the terminal
part, comprising the three outer joints, being abruptly reflexed, and thus forming with
the remaining part a more or less acute angle. The proximal part of the leg generally
extending straight forward, reaches nearly to the tip of the autennular peduncle. Of
the joints, the meral and carpal are exceedingly elongate and almost naked, as also very
movably connected with each other, the meral joint being by far the larger of the two,
and tapering somewhat towards the apex. The carpal joint is very slender, and slightly
dilated at the extremity, where it has on both edges a few short bristles. The propodal
joint is about half as long and linear in form, and exhibits along both edges a regular

REPORT ON THE SCHIZOPODA. 123

series of close upon eight spiniform ciliated setae, those on the inner edge being the
longer. ■ The terminal joint is very small, and armed with about five strong cur^'ed
spines.

The four succeeding pairs of legs (figs. 11-15) rapidly diminish in length, and are
likewise strongly geniculate, but, unlike what is observed in the first pair, exhibit a
uniform fringe of delicate bristles along their edges. The terminal joint (see fig. 12) is
comparatively short in all of them and of a conical form, whereas the two preceding
joints are nearly equal in size.

The penultimate pair of legs (figs. IG, 18) are exceedingly small, and, as a rule, com-
pletely hidden between the gills, but nevertheless have both the endopod and exopod well
defined ; the former, however, consists only of two joints, both of which are fringed with
strong ciliate bristles.

The last pair of legs (figs. 17, 19). are quite rudimentary, constituting merely a very
small linguiform, setiferous lamella, originating from a tliickened basal part, and
apparently representing the exopod.

The gills, although approximating in appearance to those in the genus Nyctiphanes,
nevertheless exhibit certain well-marked differences. The three anterior pairs (see figs.
10, 11, 13, 20) merely constitute, as in that genus, simple stems expanded at the
extremity as two short l^ranches, curving in opposite du'ections and provided along the
posterior edge with a regular series of gill-lobules. In the three succeeding pairs (see figs.
14-16, 21-23), however, besides this outer stem, another projects inward, also with gill-
lobules, which, however, are somewhat spirally disposed. The last pair of gills (see figs. 17,
24) are, as usual, the largest of all, and exhibit in every respect a normal appearance, the
outer division having along its outer edge four curved secondary stems, besides two some-
what smaller ones at the apex.

The spermatophores (fig. 25) ai'e distinctly peduncular, the distal part being expanded
into a rounded oval vesicle, whereas the proximal part forms a very narrow flexuose
stem or neck.

The pleopoda of the female are of the usual structure, and in the male the two anterior
pairs have well developed copulatory appendages. Those of the first pair (see figs. 27, 29)
are very strong, consisting of two lamellar portions folded one upon the other, the outer of
which projects as two highly chitinised processes, shghtly dilated at the apex, and exhibit-
ing a sharpened and finely serrate edge ; moreover, from a rounded prominence of this
portion springs exteriorly a short, curved spine. The inner portion, too, is drawn
out to a linguiform projection, with a small unguiform process at the tip, and has
too, on the outer side, a strong spiniform process, whereas on the inner is afiixed
the cincinnigerous lobe. The appendages of the second pair of pleopoda (see figs. 28, 30)
constitute an ii- regularly folded lamellar process, extending beyond the tip of the principal
plate.

124

THE VOYAGE OE H.M.S. CHALLENGER.

The telson (see fig. 26) exhibits the usual slender form, and has the apex some-
what produced and acutely pointed. The subapical spines are of moderate length, and
perfectly smooth. Moreover, two pairs of very small denticles occur on the dorsal face of
the telson.

The uropoda {ibid.) have the inner plate very narrow, and reaching almost to the tip
of the telson when extended posteriorly. The outer plate is a trifle shorter, Ijut much
broader, and ^irojects at the apex, exteriorly, as an acute corner.

The luminous globules agree perfectly both as to number and arrangement with
those in Euphausia.

Colour. — Some specimens in the collection, preserved in glycerine, have the whole
surface of the body, and more particularly that of the tail, dotted over with small stellate
pigment-spots of a dark reddish colour.

Habitat. — Numerous specimens of this characteristic form were collected in the
Expedition in difterent tracts of the ocean. Especially in one locality of the South
Atlantic, the species would seem, to jndge from the considerable number of specimens
obtained, to have occurred in great abundance along with Nematoscclis megaUyps, a form
of Euphausiidas to be described further on. All the specimens were taken at the surface
of the sea. The localities were as follows : —

Date.

Locality.

December 19, 1873.

South of Cape of Good Hope.

May 9, 10, 1874.

Off Australian coast.

June 14, 1S74.

Off Australian coast.

June 15, 1874.

Off Australian coast, Sydney to Wellington.

July 10, 1875.

North Pacific.

July 1875.

North Pacific, Japan to Honolulu.

October 21, 1875.'

South Pacific.

October 22, 1875.

South Pacific.

January 21, 1876.

South Atlantic, between Falkland Islands and Patagonia.

Februaiy 11, 1876.

South Atlantic, south of Buenos Ayres.

March 3 to .5, 1876.

South Atlantic, east of Buenos Ayres.

March 10, 1876.

South Atlantic.

March 11, 1876.

South Atlantic.

March 13, 1876.

South Atlantic.

Maj 6, 1876.

North Atlantic.

The same species I have also observed in the Mediterranean, at Messina.

Distribntion. — The distribution of the species w^ould accordingly seem to be very
extensive, ranging, as it does, from the Mediterranean, throughout the whole of the
North and South Atlantic, the Australian Seas, and the Pacific as far north as
Japan.

REPORT ON THE SCHIZOPODA. 125

32. Thi/sanoiissa macrura, G. 0. Sars. (PI. XXIII. figs. 1-4).

Thysanaessa macrnra, G. 0. Sars, Prelimiaary Notices on the Challenger Schizopoda, No. 30.

Specific Characters. — Form of Ijody very slender. Carapace with a single lateral
denticle posterior to the middle of lower margin; rostral projection forming a triangular
plate, broad at base, with apex acutely pointed. Caudal segments smooth above, with
very small rounded epimera. Last segment exceedingly slender and elongate, preanal
spine small, with only two denticles at posterior edge. Eyes somewhat smaller than in
Thysanoessa gregaria. Antennal scale very narrow, sublinear. First pair of legs much
smaller than in last species, meral joint scarcely reaching beyond middle of antennal scale.
Telson very slender. Inner plate of uropoda much longer than outer. Length reaching
13 mm.

Bcmarks. — This species may be at once distinguished from Thysanoessa gregaria
]>y the slender form of its body, and more particularly by the great length and slenderness
of the last caudal segment. Moreovei', the form of the rostrum is somewhat different,
and the first pair of legs much less elongate than in that species.

Description. — Most of the specimens in the collection are immature ; but a few
examples would seem to be nearly full grown. The largest of these has a length of
13 mm. They are all females.

The form of the body (see PI. XXIII. fig. 1) is much more slender than in the
preceding species, and the tail in particular is remarkably elongate and narrow ; hence
the specific name.

The carapace resembles that in the last species, both as regards its general form and
the situation of the lateral denticle, but differs in the shape of the rostral projection.
The latter (see fig. 2) is not so sharply defined from the carapace as in that species,
forming merely an appressed triangular process of the frontal margin, and terminating
in a very acute point, that reaches beyond the middle of the basal joint of the anteunulse.

The caudal segments are very narrow, almost cylindrical, and provided with very
small, rounded epimera. The last segment is remarkably elongate and slender, about as
long as the two preceding taken together, and perfectly cylindrical in form. The preanal
spine (fig. 4) is much smaller than in Thysanoessa gregaria, and armed with only two
denticles at the posterior margin.

The eyes (figs. 1, 2), although exhibiting a very similar form to those in the
preceding species, are yet by comparison appreciably smaller.

The antennular peduncle (fig. 2) would seem to be a trifle more slender, agreeing, how-
ever, in other respects perfectly as to structure with those in Thysanoessa gregaria.

The antennal scale (ibid.) likewise appears somewhat narrower, almost linear in

form.

The first pair of legs (fig. l) are not nearly so strongly developed as in the latter

126 THE VOYAGE OF H.M.S. CHALLENGER.

species, the geniculate bend between the meral and carpal joints reaching to the middle
only of the antennal scale.

The tclson (see fig. 3) is very elongate and slender, with the apex acutely pointed
and the subapical spines smooth.

The uropoda (ibid.) have the inner plate very considerably produced beyond the
outer, and reaching to tlie tip of the telson.

Habitat. — All the specimens in the collection were taken in the tow-net at the
surface of the sea. The following is a list of the localities : —

Date.

Localitj'.

December 24, 1873.
December 29, 1873.
January 23, 1874.
February 3, 1874.
February 14, 1874.
February 19, 1874.
February 14, 1876.

Southern Ocean, between Cape of Good Hope and Kerguelen.

Southern Ocean, off Kerguelen.

Southern Ocean, between Kerguelen and Heard Islands.

Antarctic Ocean, at the ice-barrier.

South Atlantic, south of Buenos Ayres.

As regards distribution, the species would therefore appear to be wholly confined
within the southern hemisphere, inhabiting, as it does, exclusively the Antarctic and
South Atlantic Oceans.

Genus 6. Nematoscelis, G. 0. Sars, 1883.

Nematoscelis, G. 0. Sars, Preliminary Notices on the Challenger Schizojjoda.

Generic Gliaracters. — Form of body and structure of e5''es and antennae almost as in
Thysanoessa. Mandibular palp very small. Terminal joint of second pair of maxillaj
likewise exceedingly minute. Maxillipeds slender, with last joint somewhat appressed
and densely setose at the inner edge ; epipodite obsolete. First pair of legs remarkably
elongate and slender, well-nigh filiform, with a bunch of spiniform setae at the apex, but
for the rest almost naked. The four succeeding pairs of legs rather short and thick,
with the terminal part not nearly attaining the length of the meral joint. Penultimate
pair of legs very small, with the endopod bi-articulate. Last pair of legs quite rudi-
mentary, forming only a lamellar setiferous plate (exopod). The two anterior pairs of
gills simple, and of a similar structure to those in Thysanoessa ; remaining pairs composed
of two distinct branches ; last pair ])y far the largest. Ovisac simple, flattened.
Luminous apparatus of the usual structure.

Remarhs. — This genus is most nearly allied to Thysanoessa, but diS"ers, among other
characteristics, very materially in the structure of the legs, the first pair of which are

KEPORT ON THE SCHIZOPODA. 127

eminently distinguished by their great length and slender form, giving them a nearly
filiform appearance, hence the generic denomination. Four different species of this genus
are represented in the Challenger collection, a synopsis of which is given below : —

without any lateral "] longer than body. Eyes very large, . . N. megalops, G. 0. Sara,

denticle. First pair l-
<jf legs J shorter than body. Eyes comparatively small, N. 7mcroj)s, G. 0. Sars.

Carapace

with a well-marked
lateral denticle.
Rostrum

acute, reaching to middle of basal joint of

antennuLT. 15ody very slender, . . N. tenella, G. O. Sara

greatly produced, reaching beyond middle of
basal joint of antennulae. Body compara-
tively short, . . ' . .A'', rostrata, G. O. Sars.

33. Nematoscelis megaloj^s, G. 0. Sars (PI. XXIII. figs. 5-10 ; PL XXIV.).

Nematoscelis megalops, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 31.

Specific Characters. — Body rather thickset, gradually tapering from before backwards.
Carapace without any lateral denticles, anterior part keeled above, rostrum exceedingly
narrow, subulate, curving gently downward. Penultimate and antepenultimate caudal
segments slightly keeled above, and jutting out in the middle of the posterior margin as
small dentiform projections. Last segment longer than preceding ; preanal spine
unguiform, with a small denticle at base. Eyes of enormous size, irregularly globose,
cornea contracted in middle. Antennal scale reaching almost to the tip of the antennular
peduncle, exceedingly slender, linear, apex naiTOwly truncate, with outer corner project-
ing. First pair of legs remarkably elongate and slender, attaining, when fully extended,
the length of the whole body, meral joint reaching far beyond tip of antennular peduncle,
propodal joint a trifle shorter than carj^al ; terminal joint very minute. Telson rather
elongate, with apex acutely 2:)roduced ; subapical spines smooth. Inner plate of uropoda
longer than outer, and projecting beyond tip of telson. Length 26 mm.

Remarhs. — The present species may be regarded as the t}iie of this genus, and is
chiefly characterised by the extraordinary length of the first pair of legs and the pro-
digious development of the eyes, as also by its remarkably narrow and curved rostrum,
and the slender form of the antennal scale.

Description. — All the specimens in the collection are females, the largest has a
length of 26 mm.

The body (PI. XXIIL' figs. 5, 6) is rather thickset and but slightly compressed,
tapering gradually from before backwards, with the tail about- twice the length of the
anterior division.

The carapace is comparatively short, and lacks every trace of lateral denticles, the
inferior margins being perfectly smooth and slightly incun-ed in the middle. The

128 THE VOYAGE OF H.M.S. CHALLENGER.

anterior part has a well-marked keel running along the dorsal face, and juts out as an
exceedingly narrow, subulate rostrum, curving gently downward, and reaching almost to
the end of the basal joint of the autennulge (see figs. 8, 9). The antero-lateral corners of
the carapace are produced into an acute lobe, overlapping at the side the basal part of the
antennte. The posterior emargination is somewhat deep, exposing as usual the dorsal
part of the last segment of the trunk.

The caudal segments diminish successively both in height and breadth posteriorly,
and have the epimera distinctly projecting beneath the ventral face, and of a rounded form
The antepenultimate and penultimate segments are slightly keeled above, the keel jutting
out posteriorly into small dentiform projections. The last segment is appreciably longer
than any of the preceding, and a little compressed, exhibiting a distinct unguiform preanal
spine, usually found armed at the base with a small secondary tooth (fig. 7).

The eyes (see PL XXIV. fig. 1) are prodigiously developed, and of larger size, perhaps,
than in any other known form of Podophthalmia. They are irregularly globose in shape,
with the cornea greatly expanded, and, as it were, di%dded into two sections by a well-
marked transverse impression running straight across the middle.

The antennular peduncle (PL XXIV. fig. 2) is rather slender, and exhibits a structure
very similar to that in the genus Thysanoessa, the basal joint being rather flattened,
whereas the two outer ones are narrow, cylindrical, about equal in length, and, taken
together, as long as the basal joint. The anterior border of the basal joint projects
somewhat above, and has, as in Thysanoessa, a distinct indentation in the middle, the
outer corner jutting out as an acute denticle, whereas the inner is obtuse and provided
with two very strong recurved seta3. The flagella are, as in Thysanoessa, very short,
scarcely exceeding half the length of the peduncle.

The antennal scale (fig. 3) exhibits a remarkably narrow, nearly linear form, and
reaches almost to the tip of the antennular peduncle ; its apex is very narrowly truncate,
wnth the outer corner projecting as a small tooth, the inner rounded off. The basal spine
is very short and quite smooth. The flagellum is poorly developed, with the peduncle
very narrow and not nearly attaining the length of the scale, the terminal part being some-
what shorter than the peduncle, and composed of sixteen to eighteen short articulations.

The anterior lip (fig. 4) exhibits the usual galeate form, with the lateral angles,
however, but slightly produced.

The posterior lip (fig. 5) has the terminal lobes somewhat expanded and triangular in
form, exhibiting exteriorly a distinct and nearly right angle.

The mandibles (fig. 6) exhibit, as to the form of the body* a perfectly normal appear-
ance, the cutting edges (fig. 7) being divided into several sharply pointed teeth. The
palp, on the other hand (figs. 6, 8), is remarkably small, not even attaining half the
length of the body of the mandible. It is, moreover, very narrow, and but sparingly
furnished with bristles, with the terminal joint exceedingly minute and lamelliform.

REPORT ON THE SCHIZOPODA. 129

Tlic firat })air of uuixilkv3 (fig. 9) are, ou the whole, developed in the usual manner.
The terminal joint is rather narrow, and bears at the apex a double series of unet|ual
bristles, some of which arc -very slender. The exognath is comparatively much smaller
than in the genus Tlujsanoessa, and forms an oval lamella, fringed along the anterior
part with a dense row of ciliated bristles.

The second pair of niaxillaj (fig. 10) exhibit a somewhat more deviating appearance,
having the masticatory lobes rcmarkal)ly broad and arcuate at the edges, with the hinder
one not subdivided by a distinct indentation. The terminal joint, or palp, is exceedingly
small, lamelliform, and somewhat constricted at the base, its apex being obtusely truncate
and edged round with slender setas. The exognath, finally, is rather small, forming
merely a slight expansion of the outer edge of the basal part, but exhibiting the usual
frinoe of ciliated bristles.

The maxillipeds (fig. 11) are rather slender and pediform, reaching, when fully
extended, almost to the middle of the antennal scale. Of the joints the meral and
ischial are nearly equal in length, the latter, however, being much more expanded and
almost lamellar. The terminal joint (fig. 12) is somewhat compressed, and exhibits along
the inner edge a dense row of comparatively short, ciliated bristles. The exopodite does
not differ in size and structure from the true exopods of the legs. Of an epipodite no
trace can be detected.

The first pair of legs (fig. 13) are ver)^ remarkable, both as regards their great length
and slender aspect, and their very peculiar structure. When fully extended, they exceed
in length even the whole body ; l)ut, as a rule, they are found to exhibit, as in Thijsanoessa,
a sharp geniculate bend between the meral and carpal joints, the terminal section being
reflexed at a more or less acute angle. The proximal part of the leg, comprising the
coxal, basal, and ischial joints, appears rather strong and muscular, exhibiting along the
inner edge a row of very small bristles. The remaining part, on the other hand, is
extremely slender, indeed almost filiform, also very brittle and therefore easily broken off
if the specimens be not handled with the greatest care. This part, moreover, lacks every
trace of marginal bristles, being quite naked throughout, save at the apex, where a dense
assemblage of peculiar spines springs forth in the form of a Ijrush. Of the joints, the
meral is much the longest, reaching far beyond the tip of the antennula), and being very
movably jointed to the ischial, exhibiting a peculiar curve at its base. The carpal and
propodal joints are likewise very slender, the former being a trifie longer than the latter,
whereas the terminal joint is exceedingly minute, and firmly connected, it would seem,
with the preceding. It bears (fig. 14) six slender, straight spines, which, together with
two similar ones originating interiorly from the end of the preceding joint, constitute the
above mentioned peculiar apical brush. The spines, when highly magnified, present a
very curious appearance, being, as it were, annulated at regular intervals, and jutting
out at each annular segment as a recurved denticle, thus giving to one of the edges a

(ZOOL. CHALL. EXP. PART. XXXVII. 1SS5.) Oo 17

]3() THE VOYAGE OF H.M.S. CHALLENGER.

densely sen-ate aspect. What the real function of this peculiarly modified pair of legs
U, I am wholly unable to state. Meanwhile, we have every reason to assume that
so remarkable a structnre cannot but stand in close connection with some unknown
requirement bearing on the vital phenomena of the animal.

The four succeeding pairs of legs (figs. 16-20) are comparatively very short and
somewhat clumsy in structure, with the joints slightly compressed and fringed along the
inner edge with slender bristles. Of the joints, the ischial and meral are the largest, and
nearlv equal in length. The terminal part, comprising the three outer joints, is
remarkably short, not nearly attaining the length of the meral joint, and exhibits
several strong spiniform bristles, six to eight of which issue from the very small terminal
joint (fig. 17).

The penultimate pair of legs (figs. 21, 22) are exceedingly small, and almost hidden
between the gills, but have l)oth the endopod and exopod distinctly defined. The
former consists, as in Thysanoessa, of only two joints, the terminal the longer, both with
a few scattered bristles along their inner edge.

The last pair of legs (fig. 22, 23) are cjuite rudimentary, each forming merely a small
laminar plate, originating from a short basal part. This plate, whicli undoubtedly
represents the exopod, is somewliat unlike that in Thysanoessa, being ratlier expanded
and liroadly truncate at the apex, which, together with the inner edge, is fringed with a
dense row of ciliated bristles.

The gills are rather fully developed, forming a broad fringe beneath the carapace
along the sides of the trunk (see PI. XXIII. fig. 10), and, as usual, increasing successively
in size from before backwards. The two anterior pairs (PL XXIV. figs. 13, 16, 24)
exhibit much the same appearance as in Thysanoessa, constituting, as they do, single
stems, expanded at the apex into two recurving corners, and with a regular series of
digitiform gill-lobules along the posterior edge. The four succeeding pairs (figs. 25-28),
on the other hand, are all of them double, or exhibit two distinctly defined stems, the
outer of which corresponds perfectly in structure with the two anterior pairs of gills,
whereas the inner stem is bent inward, exhibiting a somewhat pyramidal form, and
furnished at both edges with a clustering assemblage of gill-lobules. This stem, too, is
not, as in Tliysanoessa, connected with the outer one, but would seem to spring-
separately from the coxal joint of the leg, becoming, as usual, gradually more complex
posteriorly. The last pair of gills (fig. 29) are very large and complex in structure,
consisting of two principal portions that point in opposite directions, both, but especially
the outer one, being richly arborescent.

The pleopoda of the female do not exhibit any marked peculiarities ; those of the
male I had no opportunity of examining, the collection containing female specimens
only.

The telson (see fig. 30) is very slender and elongate, attaining nearly the length of

REPORT ON THE SCHIZOPODA. 131

the two preceding segmeuts taken together. It tapers toward the apex, produced as an
acute point. The subapical spines are of moderate size and smooth. Moreover, two
pairs of small denticles occur on the dorsal face of the telson.

Theuropoda (see fig. 30) have both plates very narrow, the inner one being appreciably
longer than the outer, and projecting beyond the tip of the telson.

The luminous globules agree perfectly, both in numljer and arrangement, with those
in Euphausia.

Habitat. — The collection contains comparatively numerous specimens of tliis
interesting species, the greater part having been taken from the surface of the sea at two
adjacent Stations of the South Atlantic. The species also occurred in two other localities,
Init much less abundantly. The localities are the following : —

Date.

Locality.

May 21, 1873.
March 9, 1876.
March 10, 187G.
March 13, 187G.

North Atlantic, off Nova Scotia.
South Atlantic (Station 331).
South Atlantic (Station 332).
South Atlantic (Station 333).

The distribution of the species therefore, as yet known, would appear to be restricted
to the Atlantic Ocean.

34. Nematoscelis microps, G. 0. Sars (PI. XXV. figs. 1-4).

Nematoscclis microps, G. 0. Sars, Preliminary Notices on the Challenger Shizopoda, No. 32.

Specific Characters. — Body somewhat more slender than in the preceding species.
Carapace without any lateral denticles, anterior part very slightly keeled above, rostral
projection straight, acute, flattened at base. Caudal segments smooth above. Ej'es
much smaller than in Nematoscelis megalops, cornea narrowed in the upjjer part.
Antennal scale projecting but slightly beyond second joint of antennular peduncle, less
narrow than in preceding sijecies, apex obtusely rounded. First pair of legs, when fuUy
extended, shorter than body, propodal joint longer than carpal, terminal joint oblong,
constricted at base, with about six spines, one of which is much longer than the others.
Telson and uropoda nearly as in Nematoscelis megalops. Length IG mm.

Remarks. — This species may be readily distinguished from the preceding by the
much smaller eyes, the less elongate first pair of legs, and the form of the rostral
projection. It is, moreover, rather inferior in size, and also a trifle more slender.

Description. — Only three female specimens of tins form were taken during the
Expedition, the largest having a length of 16 mm.

132 THE VOYAGE OF II.M.S. CHALLENGER.

The form of the body (see PL XXV. fig. 1), as compared with tliat of the preceding-
species, appears somewhat more slender, and less dilated anteriorly.

The carapace lacks, as in that species, every trace of lateral denticles, and is some-
what more elongate in proportion to its height. The anterior part is very slightly
keeled above, and juts out as an acute rostral projection, reaching beyond the middle of
the basal joint of the antennulse. This projection, too, is quite straight, Avitli the basal
part rather broad and flattened. The antero-lateral corners of the carapace are not
nearly produced to the same extent as in Nematoscelis megalops.

The caudal segments are perfectly smooth above, none of them being keeled as in
the preceding species. The epimera are comparatively small and evenly rounded. The
last segment is rather elongate, and exhibits a very small simple preanal spine.

The eyes {see fig. 2) are not nearly so largely developed as in the last species, being
comparatively small, with the cornea somewhat narrowed in its upper part.

The antennular jseduncle (ibid.) exhibits a structure closely resembling that in
Nematoscelis megaloj^s, but having the two outer joints a trifle more elongate.

The antennal scale (ibid.) does not nearly reach the tip of the antennular peduncle,
and would seem on the whole to be apparently less slender than in the last species, with
the apex obtusely rounded and the outer corner but slightly projecting.

The first pair of legs (see fig. 1) are rather slender and elongate, though not nearly
to the same extent as in the last species, being, when fuUy extended, somewhat shorter
than the body. Of the joints the meral, as in that species, is by far the longest, reaching
a little beyond the tip of the antennular peduncle. The relation in size between the two
succeeding joints is, on the other hand, somewhat different from that in Nematoscelis
megalops, the propodal joint being the longer of the two. Finally, the terminal joint
(fig. 3), though comparatively small, is somewhat more fully developed than in the aliove-
mentioned species, and also, it would seem, very movably connected with the preceding
joint. It exhibits an oblong form, being slightly dilated in the middle and constricted
at the base, and has six very unequal spines, one of which is very large and strong,
projecting far beyond the rest. No spines arise, as in Nematoscelis megalojys, from the
end of the preceding joint.

The succeeding pairs of legs, as also the gills and the pleopoda, would seem to agree
in all respects with those of Nematoscelis megalops.

The telson (see fig. 4) appears somewhat less elongate than in that species, exhibiting,
however, for the rest, a very similar aspect.

The uropoda {ibid.) have the inner plate somewhat longer than the outer, projecting
however but very little, if at all, beyond the tip of the telson.

One of the specimens, mounted in Canada balsam on a glass slide, is ovigerous. The
ova, which are rather numerous, lie enclosed wnthin a single oblong ovisac, extending
beneath the trunk, almost throughout the whole of its length (see fig. 1).

REPORT ON THE SCHIZOPODA. 133

Habitat. — The three specimens in the collection were taken at the surface of the sea
in the two following localities : —

Date.

Locality.

1
April 29, 1876.

Pacific, noith of the Sauilwieli Islands.
North Atlantic.

In the year 187G I took a few specimens of the same species in the Mediterranean at
Messina.

Hence it would seem to have a rather extensive distribution, the above-mentioned
localities lying in widely distant tracts of the ocean.

35. Nematocelis tenella, G. 0. Sars (PI. XXV. figs. 5, 7).

Nematoscelis tenella, G. 0. Sars, Preliminary Notices on the Challenger Schiopoda, No. 33.

Specijrc Characters. — Form of body very slender and elongate. Carapace with a well
marked, though small, lateral denticle behind the middle of the inferior margin ; anterior
part slightly keeled above ; rostral projection rather narrow, straight, acuminate. Caudal
segments smooth above, with very small rounded epimera. Last segment rather elongate,
preanal spine exceedingly minute. Eyes not very large, subclavate, cornea compara-
tively small and narrow. Antennular peduncle slender and elongate. Antennal scale
not projecting beyond second joint of antennular peduncle, very narrow, linear, apex
obtusely truncate. First pair of legs, when fully extended, much shorter than body,
meral joint scarcely projecting beyond antennular peduncle, propodal joint longer than
carpal, terminal joint subliuear, with only four spines. Gills comparatively simple in
structure, with short papillar lobules. Length 10 mm.

Remarls. — The specimens of this form, contained in the collection, have much the
appearance of immature animals, but will not, in my judgment, admit of being referred
to either of the two species described above, since the carapace has in all of them a
well-marked lateral denticle, totally absent in the former. Moreover, several other,
characters would seem to warrant the specific difference of the present form.

Description. — None of the specimens exceed a length of 10 mm., and all have the
appearance of being females.

The form of the body (see PI. XXV. fig. 5) is exceedingly slender and elongate,
nearly cylindrical throughout.

The carapace exhibits a form rather similar to that in Nematoscelis raicro2)s, l)ut
differs in havinc; on either side a well-marked, though somewhat small, lateral denticle,

134 THE VOYAGE OF H.M.S. CHALLENGEE.

arisino- from the inferior maroin behind the middle, or, more precisely, just above the
point of insertion of the penultimate pair of legs. Its anterior part has a distinct, though
not very prominent keel running along the middle, and juts out as a rather narrow and
somewhat flattened rostral projection, reaching about the middle of the basal joint of the
antennulas.

The caudal segments arc perfectly smooth aliove, and very narrow, with exceedingly
small, rounded ejumera. The last segment is appreciably longer than any of the
preceding, and has a very small, simple preanal spine.

The eyes (see figs. 5, 6) are not very large, and of a somewhat clavate form, with the
cornea very narrow, and occupying but a small part of each eye.

The antennular peduncle (ibid.) is very slender and elongate, attaining almost the
length of the carapace. The flagella, on the other hand, are exceedingly short, scarcely
exceeding half the length of the peduncle.

The antennal scale {see fig. 6) does not reach beyond the second joint of the antennular
peduncle, and is very narrow, linear, with the apex obtusely truncate, and the outer
corner but slightly projecting.

The first pair of legs (see fig. 5) are comparatively shorter than in either of the two
preceding species, and do not nearly attain the length of the body, wdien fully extended.
The geniculate bend between the meral and carpal joints extends to about the tip of the
antennular peduncle. The propodal joint, as in Nematoscelis micro2)S, is slightly longer
than the carpal, and the terminal joint is very narrow, almost linear, and provided with
only four slender spines, one of which projects far beyond the rest.

The succeeding pairs of legs are very small, and difficult to examine without dissection.

The gills are apparently far less complex in structure than the corresponding parts in
the two preceding species, the gill-lobules being few in number and merely papillar in form.

The caudal fan does not exhibit any essential difference from that in Nematoscelis
microps.

Habitat. — A few specimens of this slender species have been collected at the surface
-of the sea, in five different localities : —

Date.

Locality.

December 19, 1873.
October 27, 1874.
October 1874.
April 9, 1876.
April 13, 1876.

South of the Cape of Good Hope.

Samboangan to Ilo Ilo, Philippines.

Oil' JlinJanao, Philippines.

Tropical Atlantic.

Tropical Atlantic, off the coast of Africa.

The distribution of the species w^ould accordingly seem to range from the tropical
part of the Atlantic to the tract of ocean surrounding the Indian Archipelago.

REPORT ON THE SCHIZOPODA. 135

36. JSfematoscelis rostrata, G. 0. Sars (PI. XXV. figs. 8-10).

Xematnacelis mstrata, O. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 34.

Specific Characters. — Form of body much shorter and stouter than in the List
species. Carapace with a very strong lateral denticle at posterior part of inferior
margin, and a conspicuous rounded crest above anterior to the middle ; rostrum
greatly produced, reaching almost to the end of the basal joint of the antcnnulae,
straight, acuminate, broad and flattened at the base. Caudal segments smooth above,
with small rounded epimera. Eyes rather large, irregularly pyriform, cornea narrowed
in upper part. Antennal scale comparatively small, reaching scarcely to the end of
the second joint of the antennular peduncle. First pair of legs shorter than in the
other species, meral joint reaching hardly to tip of antennular peduncle, propodal
joint longer than carpal, terminal joint slightly dilating toward the tip, with five spines.
Gills and caudal fan as in Nematoscelis tenella. Length 8 ram.

Remarks. — This form also, it would seem, is represented in the collection only by
immature specimens. I have nevertheless felt warranted in establishing a new species
for their reception, differing, as they do, in several respects distinctly from any of the
preceding species. Thus, the l:)ody is comparatively much shorter, the rostrum more
produced ; and besides, the strongly developed lateral denticle of the carapace, as also-
the conspicuous dorsal crest, would seem to aiford well-marked specific characters.

Description. — The length of the specimens in the collection does not exceed 8 mm.,
and therefore this form must be regarded as one of the smallest Euphausidians. All the
specimens are females.

The form of the body (see PI. XXV. fig. 8), as compared with that of Nematoscelis
tenella, is much shorter and more thickset, as also somewhat compressed.

The carapace is comparatively short in proportion to its height, and has on either side
a very strong lateral denticle, jutting out from the hinder part of the inferior margins
about where that corresponding to it projects in Nematoscelis tenella. On the dorsal
face, moreover, a very conspicuous rounded crest occurs at some distance in front of the
middle, disappearing before it reaches the base of the rostrum. The latter is greatly
produced, extending far beyond the middle of the basal joint of the autennulai, and is
quite straight, ending in a sharp point. Viewed from above (fig. 9), the rostrum appears
broad and flattened at the base, tapering gradually toward the extremity.

The caudal segments are smooth above and appreciably broader than in the last
species, the epimera, however, being very small. The last segment is longer than the
preceding, aud has a very small simple preanal sjiine.

The eyes (see figs. 8, 9) are comparatively large, irregularly pyriform, and slightly
flattened, with the cornea oblong in form and somewhat narrowed in its upper part.

The antennular peduncle {ibid.) appears a trifle less elongate than in Nematoscelis
tenella, for the rest exhibiting a very similar structure.

13(5

THE VOYAGE OF H.M.S. CHALLENGER,

The antennal scale (see fig. 9) does not quite reach to the end of the second joint of
the autennuUir peduncle, and would seem to be a trifle broader than in the last species.

The first pair of legs (see fig. 8) are comparatively shorter than in any of the preced-
inof species, but in other respects resemble those in Nematoscelis tenella. The terminal
joint exjiands gradually toward the apex, which is abruptly truncate, and provided with
five spines, one of which projects appreciably beyond the rest.

The gills exhibit much the same simple appearance as in the last species.

The caudal fan, likewise, would not seem to exhibit any essential difference in its
structure from that in NematosceUs tenella.

Habitat. — Several specimens of this form were collected during the Expedition, but
the greater part are more or less defective. All were taken in the tow-net. The
localities are the foUomng : —

Date.

Locality.

August 27, 1873.

Tropical Atlantic, off St. Paul's Rocks.

August to September 1875.
February 1875.

Pacific.

Pacific, north of New Guinea.

March 3, 1876.

South Atlantic.

March 31, 1876.

South Atlantic.

April 6, 1876.
April 9, 1876.
April 13, 1876.
May 3, 1876.

Tropical Atlantic.

Tropical Atlantic, oif the coast of Africa.

North Atlantic.

May 12, 1876.

North Atlantic.

As regards distribution, it would appear from the above given localities, that the
species is met with throughout the whole of the iVtlautic, occurring also in the Pacific.

Genus 7. Sfylocheiron, G. 0. Sars, 1883.
Styloclieiron, G. O. Sars, Preliminary Notices on the Challenger Schizopoda.

Generic Characters. — Form of body somewhat varying in the different species. Eyes
more or less irregularly formed. Flagella of the two pairs of antennae very slender, with
few and elongate articulations. Mandibles without palp. First pair of maxillae wanting
cxognath ; second pair small, with indistinctly defined masticatory lobes, fringed with
but a single row of slender setae. Maxillipeds feeble in structure, with greatly developed
exopodite, but wanting epipodite. Legs rather dissimilar ; first pair of same appearance
as maxillipeds ; second jiair greatly produced, geniculate, meral and carpal joints very
elongate and slender, naked, propodal joint somewhat swollen, and armed with strong
spinlform bristles impinging against the curved spines arising from terminal joint, the

REPORT ON THE SCHIZOPODA.

137

two formiug together a kind of grasping organ. Succeeding legs much smaller and
rapidly diminishing in length, the two anterior pairs with proximal part much compressed,
laminar ; antepenultimate pair with endopod bi-articulate ; last pair quite rudimentary,
forming each merely a small setiferous lamella. Gills rather simple in structure, last pair
largest. Ovisac single. Only three luminous globules present, one ventral belonging to
the first caudal segment, and two lateral at the bases of the penultimate pair of legs, the
latter in the male very fully developed and supplied with an additional lens.

Remarks. — This is a very distinct genus, and characterised most prominently by
the strong and peculiar development of the second pair of legs, which are modified so
as to form grasping organs. Moi-eover, it differs in several other respects, as will be
seen from the above diagnosis, not a little from other Euphausiidse, though exhibiting
perhaps a certain affinity to the genus Nematoscelis.

Five different species of this remarkable genus are represented in the Challenger
collection. All of these are comparatively very .smaU, but undoubtedly cannot be
regarded as larval stages, since in one of the species at least, both ovigerous females
and adult males have been observed. This genus I had previously met with, having
observed one of its species in the Mediterranean, at Messina, in the year 1876.

The following is a synopsis of the species : —

distinctly carinate above, with a conspicuous rouudeil crest anterior
to the middle. Rostrum very narrow, acute. Eyes large, with
cornea narrowed in upper part, .....

Carapace -

S. carinuturn, G. 0. Sars.

but slightly keeled
above in anterior
part. Eyes

comparatively small, with cornea very much

narrowed in upper part. Rostrum acute, . S. mhmit, G. 0. Sars.

rather large, com-
pressed, with cor-
nea narrow, ob-
long. Last caudal
segment

not longer than pre-
ceding. Rostrum
acutely produced, .

exceedingly elongate
and slender. Ros-
trum very short, .

remarkably short, with rather jiroduced rostrum. Eyes exceedingly
large and thick. Outer part of second pair of legs forming a
complete chela, .......

S. longicorne, G. 0. Sars.

S. elongatum, G. O. Sars.

S. ahbremaium, G. 0. Bars.

.37. Stijiocheiron cannatum, G. 0. Sars (PI. XXVI.).

Stylocheiron carinatum, G. 0. Sars, Preliminary Jfotices on the Challenger Schizopoda, JTo. 35.

Si:>ecijic Cliaracters. — Form of body rather thickset in male, somewhat more slender
in female. Carapace short in proportion to height, distinctly carinated above, and
forming an elevated crest behind base of rostrum ; the latter very narrow and acutely
produced. Last caudal segment longer than preceding. Eyes large, irregularly

(ZOOL. CHALL. EXP. PART XXXVII. 1885.) Oo 18

13S THE VOYAGE OF H.M.S. CHALLENGER.

pyriform, cornea narrowed in upper part. Antennular peduncle shorter than carapace,
the two outer joints subequal, very slender in female, but strongly dilated in male.
Antenual scale projecting scarcely beyond second joint of antennular peduncle, oblong,
apex obliquely truncate. Second pair of legs, when fully extended, not attaining length
of body, carpal joint shorter than meral, and near the apex bearing a curved spine,
propodal joint with three strong ciliate bristles at inner edge ; terminal joint very
small, with apical spines subequal. Inner plate of uropoda longer than outer.
Lensfth 11 mm.

Bcmarlcs. — Of this species I have had an opportunity of examining several specimens,
both adult females and males, whereas the other species are represented in the collection
merely by solitary specimens. Hence, the generic characters have been chiefly based
upon an anatomical investigation of the present form, which accordingly may be regarded
as the type of the genus.

Description. — The length of the largest female specimen measures 11 mm. The
males are, as a rule, a trifle smaller.

The form of the body is somewhat more slender in the females (PI. XXVI. fig. 1)
than in the males (fig. 19), but in both it would appear, on the whole, to be rather thick-
set.

The carapace is somewhat short in proportion to its height, more especially in the males,
and lacks every trace of lateral denticles. Above it is distinctly carinate throughout a great
part of its length, the carina forming anteriorly an elevated crest which ends abruptly at
some distance behind the base of the rostrum. The latter is very narrow, perfectly straight,
and projects beyond the middle of the basal joint of the antennulas, its apex being sharply
pointed. The antero-lateral corners of the carapace are produced at an acute angle.

The caudal segments are smooth above, and furnished with comparatively small

rounded epimera. The last segment is rather elongate, about as long as the two

preceding segments taken together, and exhibits a very small, unguiform preanal spine.

The eyes are rather large, more especially in the male, irregularly pyriform, with the

cornea considerably expanded below and somewhat narrowed in its upper part.

The antennular peduncle in the female (fig. 3) is rather slender and elongate, though
a trifle shorter than the carapace, and exhibits a structure mvxch resembling that in the
genus Nematoscelis, the basal joint being considerably flattened, whereas the two outer
joints are very narrow, cylindrical, subecjual, and, taken together, somewhat longer than
the basal. Of the flagella, the outer part was broken off in all the specimens, but to
judge from the still remaining basal part, they would seem to have been extremely slender,
with narrow and elongate articulations. In the male, the antennular peduncle (fig. 21)
has a much more powerful development, the two outer joints being greatly dilated, and,
taken together, somewhat shorter than the basal. Of the flageUa, only the basal parts
remain, but, to judge from what is left, they must probably likewise have been rather

REPORT ON THE SCHIZOPODA. 139

more powerful than in the female. The outer flagellum more especially is distinguished
by a very thick, and, as it were, swollen base.

The antennal scale (fig. 4) projects but slightly beyond the second joint of the
antennular peduncle, and exhibits a regular oblong-linear form, its length being about
four times greater than its breadth. The apex is obliquely truncate, with the inner
corner projecting, the outer jutting out as a small denticle. Of the flagellum, here too
the outer part was broken oflf in all the specimens ; its peduncle is exceedingly slender
and projects far beyond the scale, with the middle joint very elongate, nearly three times
as long as the terminal.

The anterior lip (see fig. 5) exhibits the usual galeate form, but would seem to be
relatively somewhat smaller than in other Euphausiidse.

The posterior lip (fig. 6) has the terminal lobes somewhat rounded, without a
distinctly marked outer angle.

The mandibles (see fig. 5) are eminently distinguished by the total absence of the
palp. Their masticatory parts (fig. 7) appear a trifle less strongly expanded than in
most other Euphausiida3, but with the cutting edges divided in the usual manner into
several acute teeth, having likewise posteriorly a well-marked molar protuberance.

The first pair- of maxillaj (fig. 8) do not exhibit any trace of the usual lamellar
exognath, but for the rest would seem to be of normal appearance, except that both of
the masticatory lobes have a comparatively small number of setae and spines. The
terminal joint is lamelliform, oval, and, as usual, provided along the inner edge with
a double row of bristles.

The second pair- of maxillte (fig. 9) are rather small and membranous throughout,
exhibiting, on the whole, a less perfect development than in other Euphausiidse. The
masticatory lobes are only two in number and project but very little, forming merely
slight expansions of the inner edge of the basal part, fringed vdih a single row of slender
ciliated bristles. Of the lobes, the inner one is l)y far the shorter, and has only five
bristles. The terminal joint is very short, appearing as a mere direct continuation of the
basal part, though separated by a distinct transverse suture ; it is furnished with three
bristles only, springing from the inner edge. The exognath forms a slight expansion of
the outer edge of the basal part, and is fringed with about nine plumose setae, increasing
in length anteriorly.

The maxillipeds (fig. 10) have the stem, or endopodite, comparatively small, reaching
but very little beyond the basal part of the antennae, and rapidly tapering toward the
apex, the outer part being very slender. The masticatory process, issuing from the coxal
joint, is conically produced, and bears at the tip three diverging setae. The basal joint
is rather broad and compressed, and also the ischial joint is decidedly laminar, though
considerably narrower, both furnished along the inner edge with very short bristles. The
meral joint is somewhat longer than the ischial, but very much narrower, and has like-

140 THE VOYAGE OF H.M.S. CHALLENGER.

wise a row of delicate bristles along the inner edge. The terminal part of the maxilliped,
comprising the three outer joints, is extremely slender, and about equals in length the
moral joint. Of its joints, the middle one is the longest, whereas the last (fig. 11) is
exceedingly small and truncate, bearing at the tip four ciliated bristles. The exopodite
(see fig. 10) is remarkably large, projecting even beyond the tip of the endopodite, with
the basal part very elongate and muscular. The epipodite is wholly wanting.

The first pair of legs, wliicli in the two preceding genera are the ones peculiarly
modified, are in the present genus of exactly the same structure as the maxillipeds,
save their being a trifle more elongate, with the masticatory process obsolete and the
exopod somewhat shorter.

The second pair of legs (fig. 22), on the other hand, are developed in a very peculiar
manner, being altogether dissimilar to any of the others. They are very elongate and
slender, also strongly geniculate, recalling to a certain extent the structure characteristic
of the first pair in the genus Nematoscelis, but diflfering materially in the deviating form
of the two last joints. In the female (fig. 1) they are somewhat more elongate than in
the male, about equalling, when fully extended, the posterior division of the body in
length ; but in other respects they fully agree in both sexes. Of the joints, the meral
and carpal are exceedingly produced and very movably connected, the former being by
far the longer. The carpal joint exhibits at the end a slight projection of the inner edge,
bearing a short curved spine ; but for the rest both these joints are perfectly smooth.
The propodal joint is much shorter than the carpal, attaining scarcely half its length, but
appears somewhat thicker, and, as it were, swollen, as also provided at both edges with
three strong spiniform bristles, those of the inner edge being by far the longer. The
terminal joint, finally, is very small, and bears five similar l)ristles, curving in a direction
opposite to that taken Ity those on the inner edge of the preceding joint. Thus both
these outer joints form together, as it were, a kind of grasping hand, though not so
decidedly prehensile in this as in the other species of the genus.

The two succeeding pairs of legs (figs. 12, 13) difter very considerably in appearance
both from the first and second pairs. They are somewhat short, with the proximal part
of the endopod strongly appressed and laminar, as also gradually tapering toward the tip
of the meral joint. The ischial joint in both pairs is much the largest, being several
times longer than the meral ; both have a few slender bristles along the inner edge. The
terminal part is distinctly tri-articulate in the third pair (fig. 1 2), and somewhat longer
than the meral joint, whereas in the fourth pair (fig. 13) this part is exceedingly small
and only bi-articulate.

The fifth or antepenultimate pair of legs (fig. 14) present an aspect, not agreeing with
any of the preceding pairs. They are rather small and have the endopod consisting of
only three joints, the first much the largest, somewhat curved, and provided along the
inner edge with a row of eight strong ciliated setae. The succeeding (meral) joint has on

REPORT ON THE SCHIZOPODA. 141

either side, near the extremity, a very slender, non-ciliated bristle. Finally, the last
joint, representing the terminal part in the preceding legs, is exceedingly narrow, and
bears four similar bristles, one of which issues from the outer edge, the other three from
the tip ; one of the latter is extremely elongate.

The penultimate pair of legs (fig. 15) are still smaller and simpler in structure, with
the endopod consisting of only two joints of almost equal size, the terminal one somewhat
curved, and provided at the tip with four remarkably long and slender, non-ciliated
bristles. The exopod in this as well as the preceding pair is very small, though with
both its sections well defined.

The last pair of legs (figs. 16, 17) are quite rudimentary, each forming merely an
ovoid, setiferous lamella (exopod), originating from a short basal part connected with
the corresponding gill-stem.

The gills (see fig. 2) exhibit on the whole a rather simple structure, all, except the
last pair, forming single stems, more or less expanding at the tip, and bearing a regular
series of digitiform gill-lobules. On the two first pairs two such lobules only are present ;
on the succeeding paii's the number gradually increases from four to eight. The last pair
(figs. 2, IG, 24) are somewhat more complex, exhibiting the two usual divisions, the outer
of which is the larger, and bears three or four secondary gill-branches.

The pleopoda in the female exhibit the usual structure. In the male, the two
anterior pairs are slightly modified, the inner plate having a sexual or copulatory
appendage. On the first pair, this appendage (figs. 25, 2G) consists apparently of two
portions, the outer bearing at the tip two rather short and somewhat hamate processes,
together with a short curved spine, the inner portion simple lobular. On the second
pair, the appendage (fig. 27) is comparatively large, projecting for beyond the principal
plate, and exhibits at the somewhat dilated extremity several twisted lobes.

The telson (see fig. 18) has the usual slender form, tapering towards the apex, which
ti'rminates in a sharp point. The subapical spines are not very large, projecting but
slightly beyond the tip of the telson, and perfectly smooth. Furthermore, two pairs of
small denticles occur on the dorsal face of the telson.

The uropoda (ibid.) are likewise quite normal in structure, having the inner plate
somewhat longer than the outer, and reaching nearly to the tip of the telson.

The kmiinous apparatus, so uniformly developed in most other Euphausiidae, exhibits
in this genus certain well-marked peculiarities. Thus the globules are considerably
reduced in number, only three of them being developed, viz., one odd one between the
bases of the first pair of pleopoda, and a pair of lateral globules at the bases of the
penultimate pair of legs (see figs. 1, 19). On the other hand, the latter globules attain
in the male (figs. 20, 2-3) an extraordinary development, being more than twice as large
as those in the female. Moreover, a supplementary lens, formed, it would seem, by a
thickening of the outer integument, is sultjoined at some distance from the alolmle, and

142 THE VOYAGE OF H.M.S. CHALLENGER.

iu such a position as to admit of the front part of the globule being brought precisely in
the same axis. Thus, no doubt, a much more complete condensation of light may be
effected than could possibly result from the action of the globule alone. Within the
ocular pedicle occurs, moreover, in both sexes, a luminous organ, similar in structure to
the one described above in Euphausia (see fig. 1).

Of the female specimens in the collection, two were ovigerous. The ova are (see
fig. 1) very large, and of course few in number, as also contained within a common sac-
cular envelop, oblong and somewhat flattened, and extending beneath the greater part of
the trunk. The peculiar slender, non-ciliated bristles issuing from the endopods of the
antepenultimate and penultimate pairs of legs in the female, serve most probably for
aflixing the ovisac and keeping it in sihi.

Habitat. — The specimens in the collection were all taken by the tow-net, in the
following localities : —

Date.

Locality.

August 11 to 12, 1874.
October 1874.
February 1875.
March 21, 1876.

Pacific, off Kandavu, Fiji Islands.
Off Mindanao, Philippine Islands.
North Pacific.
South Atlantic.

The range of the species would accordingly seem to be rather extensive, comprising,
as it does, the South Atlantic and Pacific Oceans, as also the Celebes Sea.

38. Stijlocheiron suhmii, G. 0. Sars (PI. XXVII. figs. 1-4).

Stylocheiron suhmii, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 36.

Specific Cfiaracters. — Form of body rather short. Carapace larger than in last
species, without any distinct dorsal crest, rostral projection triangular, acute. Last
caudal segment scarcely longer than preceding. Eyes smaller than in Stylocheiron
carinatum, cornea much narrowed in upper part. Antennular peduncle in female
exceedingly slender, equalling carapace in length, last joint longer than second. Antennal
scale projecting considerably beyond second joint of antennular peduncle, very narrow,
linear, apex obliquely truncate. Second pair of legs almost as long as the body, carpal
and meral joints subequal, propodal joint with three slender spines at end of inner edge,
terminal joint produced as a strong unguiform spine and with two shorter spines
springing from either side. Uropoda shorter than telson, terminal plates subequal.
Length 8 mm.

Remarks. — Among the drawings executed by the late Dr. v. Willemoes-Suhm during
the Expedition, there is one representing this form, and as the species, therefore, may be

REPORT ON THE SCHIZOPODA. 143

said to have been discovered by that lamented naturalist, I have deemed it advisable to
associate his name with this form, although he was clearly misled in regarding it as a
male Eupliausia. The species may be at once distinguished from Stylocheiron cannatum
by the more elongate carapace, lacking, as it does, any distinct dorsal crest, by the much
smaller eyes, the very slender antennulaj, and a somewhat different structure of the
second pair of legs.

Description. — Only three specimens of this form are in the collection, the largest of
which, a female, measures 8 mm. in length. The latter, apparently the same specimen
examined by the late Dr. v. Willemocs-Suhm, has been treated with carmine and
mounted in Canada balsam on a glass slide. The two other specimens, one of which
was a male, were more or less defective, and also of smaller size.

The form of the body (see PI. XXVII. fig. 1) is rather short, and exhibits between
the anterior and posterior divisions a projDortion somewhat different from that in the
preceding species, the tail being relatively far less elongate.

The carapace appears comparatively larger than in Stylocheiron carinatum, as also
somewhat narrowed anteriorly, and without any distinct crest, being but very slightly
keeled along the middle of the anterior part. The rostral projection is shorter, and
flattened at the base, terminating in a sharp point, that does not nearly reach to the
middle of the basal joint of the antennulge.

The caudal segments rapidly diminish in height and breadth posteriorly, and are
furnished with distinct, though not very large, rounded epimera. The last segment is
comparatively short, very little, if at all, longer than the preceding, and would seem to
lack the preanal spine.

The eyes (see fig. 1), as in Stylocheiron carinatum, are irregularly pj-riform, but
relatively much smaller, with the cornea exceedingly narrowed in its u^^per part, form-
ing here (see fig. 4), as it were, a mammillar j)rojection containing a number of densely
crowded visual elements.

The antennidar peduncle, in the female (see fig. 1), is remarkably elongate and slender,
almost ec[ualling the carapace in length, and has the last joint somewhat longer than
the second. In the male this part (fig. 4) is relatively less slender, with the outer
joints subequal and cylindrical in form. Of the flagella the inner one only is complete
in the female specimen ; it has nearly the length of the peduncle, and is very slender,
with six rather elongate articulations.

The anteunal scale (fig. 2) is rather elongate, projecting considerably beyond the
second joint of the antennular peduncle, and, in the male (fig. 4), reaching nearly to the
tip of the peduncle. It is exceedingly narrow, linear, though slightly expanding toward
the apex, which is very oblicpely truncate, with the inner corner greatly projecting and
the outer having a well-defined tooth. The flngellum is remarkably elongate and
slender, exceeding even the length of the body, and has the peduncle extending far

144 THE VOYAGE OF H.M.S. CHALLENGER.

beyond the tip of the scale ; the terminal part is composed of about five very long and
slender articulations.

The second pair of legs (see fig. 1), when fully extended, almost equal in length the
whole body, and have the meral and carpal joints nearly equal. The propodal joint
is, as usual, somewhat thickened, and bears at the end of the inner edge three slender,
non-ciliated spines. The terminal joint is conically tapering, and juts out as a strong
unguiform spine, having also, on either side, two other somewhat shorter ones.

The telson would not seem to exhibit any essential difference from that in the preced-
ing species.

The uropoda, on the other hand, would appear to be relatively shorter, not nearly
reaching to the tip of the telson, and with both plates about equal in length.

Habitat. — The three specimens of this form in the collection were taken at the
surface of the sea, in the following localities : —

Date.

Locality.

October 27, 1874.
January 9, 1875.
March 1, 1875.

Samlioangan to Ilo Ilo, Philipi^ines.
Oif Luzon, China Sea.
Pacific, north of Xew Guinea.

The distribution of the species, as yet known, would accordingly seem to be confined
to the western part of the Pacific and the sea surrounding the Philippine Islands.

39. Stylocheiron longicorne, G. 0. Sars (PL XXVII. fig. 5).

Stylocheiron longicorne, G. 0. Sars, Preliminary Notices on the Ch.iUenger Schizopoda, Xo. 37.

Specific Characters. — Form of- l:)ody a little more slender than in the last species.
Carapace very slightly keeled above in anterior part ; rostral projection shorter than in
Stylocheiron suhmii, acute. Last caudal segment scarcely longer than precding. Ej^es
rather large and much compressed, with cornea very narrow, oblong, but slightly
contracted in its upper part. Antennular peduncle remarkably slender and elongate,
exceeding carapace in length, both flagella also very long and slender. Antennal scale
similar in form to that in Stylocheiron suhmii; flagellum enormously produced, with
extremely elongate articulations. Second pair of legs likewise of unusual length, longer
even, when fully extended, than the whole body, carpal and meral joints subequal, and
nearly as in Stylocheiron suhmii. Uropoda longer than telson, with inner plate scarcely
longer than outer. Length 9 mm.

Remarks. — This species is closely allied to Stylocheiron suhmii, but can be readily
distinguished by the peculiar compressed form of the eyes, as also Ijy the prodigious length
of the antennal flagellum and of the second pair of legs.

REPORT ON THE SCHIZOPODA. 145

Description. — Ouu specimeu only of this form, a female, is found in the collection,
mounted in Canada balsam on a glass slide. The specimen measures in length 9 mm.

The form of the body (see PI. XXVII. fig. 5) is somewhat short, though perhaps a
trifle more slender tliau in Sti/locheiron suhmii, the posterior division being rather more
elongate in jiroportion to the anterior.

The carapace appears relatively smaller than in the last species, exhibiting for the
rest a very similar form. The anterior part is slightly keeled above, and juts out as a
rather short but acute rostral projection.

The caudal segments are, as in the other species, quite smooth above, and provided
with well-defined, though not very large, rounded epimcra. The last segment is scarcely
longer than the preceding, and would seem to lack the preanal spine.

The eyes are considerably larger than in StijJochciron suhmii, and greatly compressed,
expanding at the end, with the cornea remarkably narrow, oblong, and but slightly
contracted in its upper part.

The antennular peduncle is exceedingly slender and elongate, more so even than in
the last species, and appreciably exceeds the carapace in length. The tiagella are some-
what longer than the peduncle, and very slender, filiform, l)otli of them five-jointed
and equal in length.

The antennal scale reaches a little beyond the second joint of the antennular peduncle,
and exhibits a certain resemblance to that in Stylocheiron suhmii, though possibly a trifle
broader. The flagellum is prodigiously elongate, perhaps several times as long as the
l)ody, the peduncle alone having more than twice the length of the carapace, with the
outer joint exceedingly narrow and linear.

The second pair of legs exhibit a structure very similar to that in Stylocheiron suhmii,
but are relatively still more produced, exceeding, when fully stretched, the w'hole body in
length.

The caudal fan would seem to differ from that of the last species in a more elongate
form of the uropoda, projecting appreciably, as they do, beyond the tip of the telson.
Both of the terminal plates are about equal in length.

Habitcit. — The above described specimen was obtained at the surface of the sea, in the
following locality : —

Date.

Locality.

December 14, 1873.

South of Cape of Good Hope.

The species also occurs in the Mediterranean, since a few specimens were taken by
myself, at Messina, in the year 1876.

(ZOOL. CHALL. EXP. PART XXXVIT. — 1SS5.) Oo 19

14G THE VOYAGE OF H.M.S. CHALLENGER.

40. Stylocheiron elongatum, G. 0. Sars (PI. XXVII. figs. 6-10).

Stylocheiron elongatum, G. (). >Sars, Preliminary Notices on the Challenger Schizo[)oda, No.';38.

Specific Characters. — Form of body very slender and elongate. Carapace somewhat
gibbous in anterior part; rostral projection very short. Last caudal segment remarkably
elongate, exceeding in length the two preceding taken together. Eyes rather large and
compressed, cornea oblong, not contracted in upper part. Antennular peduncle- nearly as
long as carapace, the two outer joints subequal and l)ut slightly dilated in male.
Antennal scale rather narrow, apex obliquely tapering to a projecting corner. Second
pair of legs rather shorter than body, meral joint longer than carpal, hand nearly as in
the two last species. Inner plate of uropotla much longer than outer. Length of adult
male 13 mm.

Remarks. — The present species is recognised at once by the very slender form of the
body, and, more particularly, the great length of the last caudal segment. Moreover,
the deviating form of the antennal scale, as also the comparatively less elongate second
pair of legs, aflford good specific characters.

Description. — Two specimens only of this distinct form were found in the collection,
one an adult male, the other a young female. The length of the male specimen is 13 mm.

The form of the body (see PL XXVII. fig. 6) is more slender and elongate by far than
in any of the other species, the tail in particular being greatly produced.

The carapace is comparatively short, measuring in length not more than a thii-d of
the tail, and would appear to be somewhat gibbous throughout its anterior part, with a
somewhat short and low crest above in the middle. The rostral j)rojection is very
short, reaching but slightly beyond the ocular segment. The autero-lateral coi-ners of
the carapace are rather produced, and very acute.

The caudal segments taper gradually from before backwards, and are furnished mth
comparatively small, rounded epimera. The last segment is remarkably elongate and
slender, exceeding even the two preceding ones taken together, and would appear to lack
the preanal spine.

The eyes are rather large, and expanded toAvard the apex, but decidedly compressed,
with the cornea narrow oblong, and of nearly uniform breadth throughout.

The antennular peduncle in the female specimen is very slender and elongate ; that of
the male is comparatively more thickset, with the two outer joints somewhat less narrow
and about equal in length. The flagella were broken ofi" in both specimens.

The antennal scale (fig. 7) is not very elongate, reaching but slightly (in the male)
beyond the second joint of the antennular peduncle, and exhibits a form somewhat
dissimilar to that in the other species, being broadest in the middle and tapering
gradually towards the apex, which is not truncate, but ends in a projecting corner. The

REPORT ON THE SCHIZOPODA. 147

flagellum was partly broken ofl" in the specimens examined, and innoue of them would
appear to have had any considerable length.

The second pair of legs (see fig. 6) are relatively much shorter and stouter than in
any of the three preceding species, not nearly attaining the length of the body. Of the
joints, the meral is appreciably longer than the carpal. The propodal joint (fig. 8) is
rather swollen, and has, as in the two preceding species, at the end, interiorly, three
curved spines, one of which is very elongate. The terminal joint is conical in fonn, and
bears five spines, three apical and two lateral.

The copulatory appendages of the two first pair of pleopoda in the male (see figs.
9, 10) are rather fully developed, more especially those of the first pair (fig. 9), and
exhibit a structure somewhat resembling that in Sti/locheiron carinatum.

Both the telson and the uropoda appear rather more elongate than in the three
preceding species, the inner plate of the uropoda, in particular, being greatly produced,
and reaching appreciably beyond the tip of the telson.

The remarkably developed luminous globules occurring at the bases of the pen-
ultimate pair of legs are distinctly perceptible in the male specimen (fig. 6) shining
through the integument ; and, moreover, a supplementary lens may be seen in front of
each globule, precisely as in the male of Stt/Iocheiron cannatiim.

Habitat. — The two above mentioned specimens were taken at the surface of the sea,
both in exactly the same locality, along with specimens of Thysano'dssa gregaria and
Nematoscelis megalops; March 187G, South Atlantic.

41. StyJocheiron abhreviatum, G. 0. Sars (PI. XXVII. figs. 11-13).

Stylocheiron abhreviutum, G. 0. Sars, Preliminary Xotices on the Challenger Schizopoda, No. 39.

Specific Characters. — Form of body exceedingly short and thickset. Carapace
remarkably shortened, with a slight rounded crest above ; rostrum rather large, straight,
lanceolate, tip very acute and somewhat deflexed. Last caudal segment longer than
preceding. Eyes enormously developed, pedicle very tumid, cornea narrowed in its
upper part. Antennular peduncle elongate and slender, the two outer joints subequal.
Autenual scale projecting beyond second joint of antennular peduncle, sublinear, apex
narrowly truncate, outer corner armed with a very small tooth. Second pair of legs
shorter than body, carpal joint only half as long as meral, propodal joint rather elongate,
and forming, together with the terminal, a complete chela. Inner plate of uropoda a
trifle longer than outer. Length 8 mm.

Remarks. — This species can, at the first glance, be recognised by its very short and
thickset body, its enormous eyes, and the peculiar structure of the second pair of legs,
the two outer joints of which form together a complete chela.

148 THE VOYAGE OF H.M.S. CHALLENGER.

Description. — Several, but the greater part defective, specimens of this striking form
are met with in the collection, the largest of wliic^li has a length of 8 mm. All
si:)ecimens would seem to be females.

The form of the body (see PI. XXVII. fig. 11) is exceedingly short and thickset,
more so perhaps than in any other known species of Euphausiidae.

The carapace, in particular, is remarkably shortened, almost as high as long, and
al)ove has a distinct, though not very elevated, rounded crest. The rostral projection
is rather strong, lanceolate, and terminates in a, very acute and somewhat deflexed
point.

The five anterior caudal segments are somewhat thick, and furnished with compara-
tively small, rounded epimera. The last segment, on the other hand, is very elongate
and tapers toward the apex. Of the preanal spine, no trace whatever could be
detected.

The eyes are prodigiously developed, with very thick, and, as it were, swollen
pedicles, and the cornea somewhat expanded below but apprecial)ly narrowed in the
upper part.

The antennular peduncle is rather elongate, with the two outer joints very slender
and about equal in length. Both of the flagella were broken in all the specimens.

The antennal scale (fig. 12) is rather large, reaching to well nigh the middle of the
last joint of the antennular peduncle; it exhibits a narrow, linear form, being somewhat
curved and narrowly truncate at the apex, with the outer corner projecting as a small
denticle. The flagellum is very slender, with its basal part exceedingly narrow and
projecting far beyond the tip of the scale, having also the middle joint by far the
longest.

The second pair of legs (see fig. 11) do not attain, when fully extended, the length
of the body, and have the carpal joint scarcely more than half as long as the meral.
The propodal joint, on the other hand, is more produced than in any of the preceding-
species, attaining well nigh the length of the carpal, and juts out at the end interiorly
as a strong unguiform spine. The last joint is digitiform -produced, and terminates in a
strong incurved claw, lieariug at its base two secondary spines. This joint, too, admits
of being impinged against the sjiine arising from the preceding joint, and thus consti-
tutes with the latter a complete chela, in appearance somewhat resembling that in
several Decapods.

The caudal fan does not exhibit any marked peculiarities. The inner plate of the
uropoda is, however, somewhat longer than the outer, and projects a little beyond the
tip of the telson.

Habitat. — The specimens were taken at the surface of the soa, in the following
localities : —

REPORT ON THE SCHIZOPOD.\.

149

Date.

Locality.

July 1875.
April 9, 1876.
April -29, 1876.

Pacific, north of Sandwicli Islands.
■ Tropical Atlantic.
North Atlantic.

Hence the species would seem to have a rather extensive clistrihntion, ranging, as
it does, from the North Athmtic to the Pacific Ocean.

DEVELOPMENT OF EUPHAUSIID^E.

In his great work on the Crustacea of the United States Exploring Expedition, Dana
has established, exclusive of certain other spurious genera, apparently founded on larval
forms of Macrura, the three following schizopodous genera : — Cyrtopia, FurciUa, and
Cahjptopis. The first of these he ranks among the Euphausiidse, whereas the two others
are described in an Appendix to the Mysidse together with the spurious genus Zo'ea (first
larval stage of Brachyura). As first shown by Professor Claus,^ all these three genera
represent but different stages in the development of Euphausiidse, the genus Calyptopis
beino- an earlier, the genus Cyrtopia a later, and the genus FurciUa an intermediate
stage. In 1869 Metschuikoff described'' a still earlier stage in the development of
Euphausia, and in 1871 the same author stated'' that the young of Euphausia are
hatched as true Nauplii, having a rounded, unsegmented body with only three pairs of
developed limbs, viz., the two pairs of antennae and the so-called mandibular legs. Thus
not less than five principal stages occur in the larval development of the Euphausiidaj.
The two first we shall designate, in accordance with earlier authors, the Naitplius stage
and the Mctanauplius stage. For the three succeeding stages I have seen fit to apply
the generic denominations suggested by Dana, since none of these stages fully correspond
with the Zoea and Mysis stages in other Podophthalmia. Hence we have the following
successive stages in the development of the Euphausiidas. The Nauplius, Metanauplius,
Calyptopis, FurciUa, and Cyrtopia stages .The first of these I have not had opportunity
of examining, whereas the following will all be found described in detail below, as well
as several intermediate or connecting stages.

I append here a short diagnosis of each of the principal stages peculiar to the
development of the Euj^hausiidse : —

1. NaupUus Stage. — Body oval, unsegmented. No compound eyes. Three pairs of

1 Ueber einige Schizopodeu und niedere Malacostraken Messina's, Ztilschr.f. uiss. Zonl., 1863.

2 Ueber ein Larvenstadium von Euphausia, Zdtschr.f. wiss. Zrol., Bd. .\i.\.

3 Ueber den Naupliuszustand der Euphausia, Zeitschr. f. wiss. ZooL, Bd. .\.\i.

150 THE VOYAGE OF H.M.S. CHALLENGER.

limbs oiilv present, the anterior (antennulse) simple, the two others (antennae and
mandibular legs) biramous, natatory.

2. Metanauplms Stage. — Form of body as in the Nauplius stage. Two pairs of
limbs (anteunul£B and antennae) only developed; mandibular legs lost. Mandibles,
maxillfe, and maxillipeds present merely as bud-like prominences.

3. Calyptopis Stage. — Body divided into its two principal divisions. Carapace
distinct, forming anteriorly a hood-like expansion. Tad becoming segmented. Com-
pound eyes still imperfectly developed, immobile, and covered over by the carapace.
Mandibles, maxillfe, and maxUlipeds distinct, but no trace of legs or pleopoda. Uropoda
becoming developed.

4. Furcilia Stage. — Compound eyes more fuUy developed, mobile, and projecting
beyond the sides of the carapace. Antennae still retaining their original structure,
natatory. Anterior pairs of legs and pleopoda successively developing.

5. Cyrtopia Stage. — Antennular flagella becoming elongate and distinctly articulate.
Antennae transformed, so as not to serve the purpose of locomotion. Posterior legs and
gUls successively appearing.

6. Post-Larval Stage. — iVll the legs developed. Telson assuming its definitive form
and armature.

The difficulty attending an accurate reference of the numerous larval forms contained
in the Challenger surface gatherings to the several species described above has been very
great. However, by carefully examining all the forms, and comparing one with the
other, I have nevertheless been enabled to trace out the development, more or less
completely, in four different species belonging to as many genera. In the following
pages I purpose describing the several stages of each sj)ecies in detail.

Early Larval Stages of Nyctiphanes australis, G. 0. Sars (PL XXVIIL).

The larvae treated of here I have felt warranted in referring to the above-named species,
taken, as they were, from precisely the same bottles as the adult specimens of this form,
and from localities where no other Euphausiidae were obtained. Moreover, as stated above,
two of the adult females were ovigerous, whence it may be inferred that hatching time
was about to commence. From this cause, apparently, no older larval stages than those
here described were found in the jars.

Metanauplius Stage (figs. 1-3). — This is the earliest stage known to the author, and
that, it would seem, immediately succeeding the true Nauplius stage. It was represented
by a solitary specimen, which measured only -g mm. in length.

The body is oval in form and does not exhibit the slightest trace of segmentation, nor
any distinct limitation of the two principal di\asions, so well defined in the adult animal.

The carapace is, however, distinctly indicated even at this early stage, forming, as it

REPORT ON THE SCHIZOPODA. 151

were, au evenly arched cl3'peifbrm sliiekl, that covers about the whole of the body,
except a small obtusely conical part jutting out behind, and representing the inidi-
mentary tail. It constitutes in the greater part of its extent the immediate wall of the
body, being free only in its marginal zone, where it forms merely a slight fold,
covering at the sides the bases of the budding limbs back to the oral opening.

Of the compound eyes, no trace whatever can be detected. Onh^ a small spot of
black pigment is observed anteriorly on the median line, and somewhat ventrally,
representing the simple larval eye, or ocellus, which, as stated above, also occurs in the
adult animal between the insertion of the compound eyes.

Posterior to the ocellus, and between the points of insertion of the antennae, may
be seen inferiorly a rather large carneous prominence, continuous anteriorly with the
front part of the body, whereas, posteriorly, it ends as a free, arcuate edge. This
prominence represents the anterior lip, arching partly over the oral aperture.

The posterior lip, on the other hand, is in this stage Cjuite rudimentary, forming
simply two slight transverse prominences (see fig. 3), which do not as yet mark off
the oral aperture posteriorly, but lie at a considerable distance behind it, between the
budding maxilla.

Of limbs, only two pairs occur fully developed, representing the antennulse and
antennae, both of which, but especially the latter, seiwe as natatory organs.

The antennulse spring from the ventral face of the body at a short distance from its
anterior extremity, and point, as a rule, straight forward. They consist of a slender
nou-articulate stem, about half the length of the body, curving slightly outward at the
extremity, which tapers to an obtuse point and bears a few slender setse, one of which
is rather elongate.

The antennfe, originating at a short distance posterior to the antenuul^e, are exceed-
ingly mobile, and constitute the chief locomotive organs, by the powerful strokes of
which the little animal is rapidly propelled through the water. They are of nearly the
same length as the antennulte, but rather dissimilar in structure, consisting of au
indistinctly biarticulate and somewhat curved basal part, or stem, from the end of which
spring two narrow cylindrical branches of ec|ual size, provided at the tip with several
slender and delicately ciliated setae.

In addition to the parts described above, occur, along the ventral face of the body,
four pairs of rounded transverse prominences, arranged symmetrically on either side,
and separated in the middle hj a narrow interstice. These prominences, very soft in
consistence, and densely cellular in structure, represent the first traces of as manj-
Hmbs, viz., the mandibles, the two pairs of maxillae, and the maxiUipeds. None of
them, however, exhibit as yet the slightest trace of segmentation, or any armature
of spines or bristles, forming merely simple buds of the body-wall.

The anterior pair of these buds, the mandibles. Lie immediately behind the points of

152 THE VOYAGE OF H.M.S. CHALLENGER.

insertion of the antenuse, on cither side of the free edge of the anterior lip, separated
as yet in the middle by a rather broad interstice. They are comparatively small,
elliptical in form, and, on the outer side, drawn out to a conical point, the rudiment
of the powerful biramous mandibular legs occurring in the Nauplius stage.

The three succeeding pairs lie in close contact with each other, forming rather broad
transverse intumescences, which, at the inner corner, jut forth as rounded, somewhat
posteriorly pointing lobes, double on the last pair (the maxillipeds).

The part of the body posterior to the above described parts, constituting the rudi-
ment of the tail, is cpiite smooth, and somewhat flattened at the extremity, which is
broadly truncate, with a very faint emargination in the middle. On either side of the
emargination three very short spines are seen to arise from the edge.

First Calyptoins Stage (figs. 4-19). — The body has in this stage a length of about
1 mm., and exhibits (see figs. 4, 5) a more distinct limit between an anterior and a
posterior division, the latter being, however, as yet much shorter than the former.

The carapace is now more fully developed, with the free portion broader, manthng
over, as it were, the bases of the limbs, and forming anteriorly a hood-like " expansion,
that covers from above the anterior extremity of the body. The free edges are c[uite
smooth and evenly curved, without teeth or projections, forming, however, a slight
incurvation at the sides of the buccal area.

The posterior di\'ision of the body lacks as yet every trace of segmentation,
constituting merely a simple, cylindrical projection, generally bent at a more or less
distinct angle. It is, however, rather mobile, and admits, by the aid of a well-defined
assemblage of muscles adjoining it on the upper face, of l)eing stretched in nearly the
same axis as the anterior division. At the extremity it is somewhat flattened and
abruptly truncate, and has the terminal edge (see fig. 19) armed with a row of twelve
strong ciliated spines, the six median about ecpial, the outer three on either side rapidly
increasing in length to the innermost, which is very large and projected far beyond the
rest. Besides the above-mentioned terminal spines a pair are seen arising from the
ventral face at some distance from the extremity, each of the spines originating a little
within the lateral edge.

Immediately in front of the posterior division of the body may be observed a faint
and close wrinkling of the integument as a first indication of the segmentation of the
trunk (see fig. 6).

The ocellus is distinctly perceptible, placed in the middle line at some distance from
the anterior margin of the carapace (see fig. G). When highly magnified (fig. 7) it is
found to contain two small refracting bodies protruding from the pigment anteriorly.

On either side of the ocellus, and somewhat dorsally, occur beneath the hood-like
expansion of the carapace (see figs. 4, 5) two large cellular bodies, of a somewhat
compressed, semicircular shape, but as yet, however, comparatively indistinctly defined.

REPORT ON THE SCHIZOPODA. 153

These bodies represent the first indication of the compound eyes ; Init neither pigment
nor any trace of visual elements have appeared. All that can now be seen within these
corpuscles consists of a bunch of densely crowded, glistening posteriorly diverging fibres,
easily recognised as representing the peculiar luminous organ that occurs in the pedicles
of the eyes of the adult animal.

The anteunulse (fig. 8) still constitute simple, somewhat curved stems, tapering
toward the apex, but differ from those in the preceding stage in the apical part being
marked off from the remainder as a distinct terminal joint, rei)resenting the outer
flagellum. This joint juts out interiorly as a small denticle, bearing, moreover, at the tij),
three slender bristles, and two translucent sensory appendages of unequal length. Of the
inner flagellum, no trace has yet appeared, its place Ijeing occupied merely by two
bristles springing from the end of the basal section or peduncle.

The antennae (fig. 9) have the two segments of the basal part more distinctly defined,
the distal segment being somewhat shorter than the proximal, and slightly dilated toward
the end. The terminal branches, too, appear more fully developed and nearly as long a.s
the basal part. The inner liranch is simple cylindrical and iiDU-artieulate, bearing at the end
four very long ciliated setre and at the inner edge two smaller ones, the proximal setae,
very short and sj^iniform. The outer Ijranch, on the other hand, has the apical part,
rapidly tapering, and di\dded into several (about five) ver}' short articulations, provided
at the inner edge with slender natatory setae, successively diminishing in length toward
the apex.

The anterior lip (see figs. G and 10) has become more distinctly marked ofi" from the
body-wall, forming a rather large oboval prominence, the posterior edge of which covers
over the inner ^Jart of the mandibles.

The posterior lip (fig. 11) exhibits quite a normal aspect, its lobes being irregularly
rounded and delicately ciliate along the inner edge.

All the three ventral limbs — in the preceding stage but faintly indicated — have now
become active organs for conveying food to the mouth ; hence they are mobile and armed
with bristles and spines (see fig. 6).

The mandibles (see figs. 10, 12) have the inner (masticatory) part expanded in the
usual manner, and exhibit, moreover, anteriorly an acute projection arising, it would seem,
from the point where, in the Naujilius stage, the mandibular leg originates. Of a palp,
on the other hand, no trace whatever can be found. The armature of the cutting edges
(see figs. 13, 14) is well developed, though somewhat dissimilar to that in the adult
animal, resembling rather the armature found in some Mysidae. As occurs in the latter,
the anterior part is divided into several strong and very closely arranged teeth, forming
together two partly superposed portions, which in the two mandil)les exhil)it a somewhat
different shape. Between this dentate part and the molar jirotuberance occurs a short
dentiform projection, and at the base of the latter is affixed on both mandibles a very

(ZOOL. CHALL. EXP. PART XXXVII. 188?.) Oo 20

1^34 THE VOYAGE OF H.M.S. CHALLENGER.

peculiar narrow ]»late, somewhat expanded at the extremity, and having the apical edge
finely denticulate. This plate (fig. 15), wanting entirely in the adult animal, would
appear to be movably connected with the mandible, since it is very easily disengaged.

The first paii' of maxillae (fig. IG) exhibit all the parts observed in the adult animal,
though they are of a somewhat dissimilar form and armature. Of the two masticatory
lobes, the inner lobe is linguiform, and furnished with eight strong ciliate bristles,
whereas the outer is truncate at the extremity, and armed with only two thick, digitiform
spines ciliate at the tip, exclusive of a simple bristle originating between the spines. The
terminal joint or palp is oval, not constricted at the liase, and provided with six bristles,
three of which spring from the tip, and three from the inner edge. The exognath is
very small, forming only a minute knob-like projection furnished with four strong ciliate
setae, one very long and reflexed, whereas the three others are directed anteriorly.

The second pair of maxillae (fig. 17) present a more deviating appearance, being
rather narrow, with the inner edge divided into five small rounded lobes, provided with
long cihate setae. The terminal joint is lamellar, and oblong in form, and bears at the
rounded tip four curved setae. Of a distinct exognath no trace can be found, the outer
edge of the basal part being not in the least expanded, and furnished only at the distal
part with a single ciliate bristle.

The maxillipeds (fig. 18) are in appearance totally different from those in the adult
animal, having more properly the character of maxillae than of legs. They consist of a
rather l)road and flattened basal part, divided into two distinct segments, and of two short
terminal branches, the inner representing the endopodite, the outer the exopodite. The two
segments of the basal part (the coxal and basal joints) have their inner edges somewhat
expanded and setiferous, four slender cihate setae springing from the proximal segment,
and four shorter ones from the distal Moreover, a minute spine occurs between the two
outermost setae of the distal segment. The endopodite scarcely exceeds half the length
of the basal part, and consists of two well-defined joints ; the proximal is broader than
long, and bears at the inner edge a short spine and a ciliate bristle, whereas the distal
joint is ovate, and provided at the tip with four slender curving setae. The exopodite is
about the same size as the endopodite, but consists of only a single oblong joint, bearing
four slender apical setae. Of an epipodite, no trace whatever can be detected.

No other' limbs are as yet developed, and, with the exception of the antennulae and
antennae, they all serve, as true oral organs, for conveying food to the mouth.

Second Calyptopis Stage (figs. 20-22). — In this stage the larva has a length of 1^ mm.,
and is chiefly distinguished (see fig. 20) Ijy a more perfect development of the tail, which
has now fully attained the length of the carapace, and is also divided into seven distinct
segments. The last of these, representing the telson (fig. 22), is somewhat spathulate at
the end, and exhibits along the edge an armature similar to that in the preceding stage,
except only that an additional spine has appeared in the middle of the apical edge, and

REPORT ON THE SCHIZOPODA. 155

somewhat shorter than the rest. Beneath the outer integument can lie faintly traced at
the base of the telsou two oval phxtes, the budding uropoda.

The cellular masses, representing the compound eyes, are somewhat more distinctly
defined, and exhil)it the fascicle of luminous fibres unaltered, whereas in the anterior
part a small pigmentary spot has appeared, the first trace of the ocular pigment.

The antennulse (fig. 21) have now become divided into a cylindrical, triarticulate
peduncle, and two rudimentary flagella, the outer of whi(;h represents the terminal joint
of the antennulfe in the preceding stage, whereas the much smaller inner flagellum has
appeared in the present stage.

In the structure of the other limbs no difference can be observed from that in the
preceding stage.

Third Calyptopis Stage (figs. 23-26). — This stage corresponds very nearly with the
earliest stage of Euphausia, as figured by Professor Claus. The animal measures
2'20 mm. in length, and has (see fig. 23) the tail still more developed, ajjpreciably
exceeding the carapace in length.

The eyes, still completely covered over by the hood-like anterior exi^ansion of the
carapace, are almost globular, and exhibit, besides a somewhat more extensive
accumulation of pigment, also the first faint trace of visual elements.

The antennulse (fig. 24) are more powerfully developed, and from the outer corner of the
basal joint juts forth a strong, anteriorly pointing spine, denticulate along the inner edge.

The other limbs belonging to the anterior division have remained nearly unaltered,
with this exception, that the outer masticatory lobe of the first pair of maxillae (fig. 25)
has a greater number of spines, viz., five.

At the base of the telson (see fig. 26) the uropoda have developed, but are still very
small and without any marginal setse, exhibiting, however, their two terminal plates
though not yet defined from the basal part. Of these, the outer is much the larger, and
juts out at the end exteriorly as a strong spine, whereas the inner plate is very small
and merely papillar in form.

No trace whatever either of legs or pleopoda can as yet be detected.

Of the inner organs in this and the preceding stages but little can of course be
observed in the spirit-specimens. Having, however, thoroughly examined in this respect
corresponding stages of the northern species, Nijctiphcmes norverjica (M. Sars), in a li^nng
state, I am enabled to confirm the correctness of the statements respecting the inner
organisation of the larvaj given by Professor Claus in his above quoted treatise.

Development of Euph.\usia pellucida, Dana (Pis. XXIX., XXX.).

Of this form, the most frequent of all the Challenger Euphausiida), numerous lan'a^
in different stages of development were found in the surface-gatherings sent me for

156 THE VOYAGE OF H.M.S. CHALLENGEE.

examination, and tluis T liavc lieen enabled to trace the development of this species
through all its numerous successive stages comprised between the second Calji^topis
stage and the adult form. Of still earlier stages, on the other hand, no examples were
found in the collection, and hence I have deemed it advisal)le to treat of the develop-
ment of the present form next after NyctijyJianes australis, of which the earliest larval
stages found have been described above.

"With a view to show the progressive development of the several liml)s, I have
carefully dissected specimens of all the stages here described ; and in PL XXX. series
of figures of the same limbs, in different stages of development, have been given. I
first propose to describe in general the more marked stages, and then shall pass
on to a detailed investigation of the chief modifications the limbs undergo during
development.

A. General Description of the successive Larval Stages (PI. XXIX.).

Second Calyptopis Stage (figs. 1, 2). — From the corresponding stage of Nyctiphanes
australis, this is easily recognised Ijy the spine-like projection formed by the carapace
posteriorly, as also by the anterior margin of the hood-like frontal part being finely
denticulate. Moreover, the terminal segment of the tail (telson) would appear to
be somewhat more produced and slightly deviating in its armature. In all other
respects the larva closely resembles the corresponding stage of Nyctiphanes. Length
of body 1^ mm.

Last Calyptopis Stage (fig. 3). — This is precisely the same stage figured by Professor
Claus in his treatise referred to above. It corresjaonds to the last described larval stage
of Nyctiphanes, from which, however, it differs, in addition to the characters distinguish-
ing the former stage, by the presence, on either side, of a well-marked lateral denticle
projecting from the lower margin of the carapace posterior to the middle. Length
of body 2-20 mm.

First Ftircilia Stage (figs. 4, 5). — The most prominent feature distinguishing this
stage from the two preceding ones, is the pronounced development of the compound
eyes, which have now become mobile and freely projecting beyond the edges of the
carapace, instead of, as in the Caly^^topis stages, being immolnle and hidden beneath
the hood-like frontal part of the carapace. In accordance therewith, the anterior part
of the carapace is somewhat altered, a distinct emargination having apj)eared on either
side, limited beneath by an acute angle (the antero-lateral corners), and marking ofi" in
the middle a broad frontal plate arching over the basal part of the eye-pedicles and the
antennular peduncles (see fig. 5). This plate has a somewhat cordiform shape, being
slightly produced in the middle, and having the lateral edges evenly curved and finely
denticulate.

REPORT ON THE .SCHIZOPODA. 157

As regards the limbs, the aiitcuuuhe, the anteniue, the mauJiljlus, tlie two pairs of
maxillae, and the maxillipeds are nearly of the same appearance as in the precedino'
stage. Now, however, the first traec of two additional pairs df linihs liave made their
appearance, the one occiu-ring immediately l^ehiud tlic maxillipeds and representing the
first pair of legs, the other placed on the first caudal segment and representing tlie
first pair of pleopoda. Meanwhile, both have still the character of simple, non-
articulate, conical processes, without exhibiting the slightest trace of bristles or any
other form of armature. Moreover, the uropoda have increased somewhat in size, and
the terminal plates have become distinctly defined from the hasal part, and furnished at
the tip with a. few slender setas. The length of the lar\'a in this stage is 2'65 mm.

Intermediate Furcilia Stage (fig. G).— In this stage the carapace has lost its
posterior spiniform projection, and the frontal plate has become narrower and more
pointed. The two additional limbs mentioned above, and forming, in the preceding
stage, merely simple non-articulate processes, have become more fully developed, being
distinctly articulate and provided with a few setae, and the first pair of pleopoda are
even, in living specimens, found to act as swimming organs. In addition, several
other budtling limbs may be observed, viz., immediately posterior to the newly formed
first pair of legs, the first trace of the following (second) pair of legs, and on each of
the four medial caudal segments a jaair of small conical processes, representing the
corresponding pleopoda. Moreover, three of the luminous globules have made their
appearance, viz., the foremost pair- on the trunk, lying within the coxal joints of the first
pair of legs, and the most anterior of the odd globules belonging to the tail. The
telson and uropoda, finally, have slightly altered in form, the former being now some-
what narrower, and the latter a trifle more produced. Length of the larva 3 "20 mm.

Last Furcilia Stage (fig. 7). — In this stage all the pleopoda have become developed,
and act in the living animal as true swimming organs. On the trunk the second pair
of legs have become articulated, though they are still much smaller than the first, and
behind it a few minute bud-like jirojections may be seen, apparently representing two
additional pairs of legs, besides the first trace of the gills. The antenna) until now
have retained their original form and function unaltered, acting as powerful natatory
organs, but in some specimens belonging to this stage the long plumose seta} are found
to l)e partly obliterated, thus proving their original function as swimming organs to be
nearly finished. The frontal plate of the carapace has lost its marginal dentition, and
is very narrow, assuming accordingly a form more in relation with that of the adult
animal. Length of the body 3 '60 mm.

First Cyrtopia Stage (fig. 8). — The character distinguishing most prominently this
stage from those preceding it, is the total change in structure and function of the
antennae. These limbs now cease entirely to act as swimming organs, and hence have
lost their_ great mobility, being now invariably extended forwards, and not, as in the

158 THE VOYAGE OF H.M.S, CHALLENGEE.

preceding stages, sideways. Of the two branches, the one has assumed the character of
the scale, the other of the flagellum. Both flagella of the antennulaj have become
considerably elongated and divided into distinct articulations. The two anterior pairs
of legs are more fully developed and nearly equal in size, both having acquired
the geniculate bend characteristic of the adult animal. Posterior to these, another pair
of legs have developed, and the gills are distinctly visible, though still exhibiting a
very simple structure. The hindmost pair of luminous globules on the trunk have
just appeared, and on the tail all the globules are quite distinct. Length of body
3-80 mm.

Last Cyrtopia Stage (fig. 9). — In this stage the flagellum of the antennge has
increased considerably in length, and its basal part is clearly defined from the terminal
part. On the trunk occur three pairs of distinctly developed, geniculate legs, and
behind them another much smaller pair have made their appearance. The endopodite
of the maxillijjeds is somewhat prolonged, and has a more pronounced pediform appear-
ance. Finally, the gills are somewhat more complex in structure than in the preceding
stages. Length 4" 15 mm.

First Post- Larval Stage (fig. 10). — The full number of legs is now developed, and the
animal, on the whole, exhiljits all the characters distinguishing the adult form, except that
the flageUa of the antennulse and antennae have not yet attained their full length, that
the gills are still comparatively simple in structure, and, finally, that the anterior pair of
the lateral denticles of the carapace are not yet developed. Length of the animal in
•this stage about 5 mm.

B. Development of the several Appendages of the Body (PI. XXX.).

The Comp)ound Eyes (fig. 9). — In the Nauplius and Metanauplius stages these
organs are entirely wanting, as shown to be the case in the last of these stages in
Nyctiphanes. In the Calyptopis stages they are still very imperfectly developed,
forming immobile rounded masses, wholly covered by the carapace and devoid of anj-
distinctiy developed visual elements. In the last only of these stages a faint trace of the
ocular pigment and a few radiating stripes may be seen in the anterior part of the eyes.
Not till the Furcilia stages do the organs (fig. 9) become mobile and pedunculate, as also
freely projecting towards either side. The cornea has become formed, but its areolation
is still imperfect, and the visual elements, radiating from the ocular pigment, are
■mequaUy developed, those in the middle being still quite rudimentary. The luminous
ascicle, distinct in the earliest stages, has now a narrow ring of red pigment coating on
the base. The following development of the eyes proceeds quite gradually, and as early
as- the Cyrtopia stages, they exhibit much the same appearance as in the adult animal,
though comparatively smaller and less expanded at the tip.

REPORT ON THE SCHIZOPODA. 159

The Antennulce (figs. 1-5). — These limbs, constituting in the Xuuplius and Meta-
nauplius stages simple, nou-articuhxte stems, exhibit each of them (fig. 1) in the earliest
Calyptopis stage described above, and apparently corresponding to the second Calyptopis
stage of Nyctiphanes, a slender non-articulate peduncle, 'bearing at the apex two very
small, uniarticulate flagella, the outer a little longer than the inner, and provided with a
pair of slender bristles and two sensory appendages.

In the following (last) Calyptopis stage, these limljs (fig. 2) are much moi-e fully
developed, the peduncle being rather strong, and di\dded into three distinctly defined
joints, of which the basal is b)' far the largest, and 2)rojects at the end exteriorly as a
strong spine, denticulate at the inner edge, and reaching almost to the end of the
peduncle. The second joint is quite short, and bears at the inner edge two strong
ciliate setse. The last joint is almost twice as long, and has a single bristle internally.
The flagella do not exhibit any essential difference from those in the preceding stage.

In the Furcilia stages the number of bristles along the inner edge of the peduncle
has become somewhat augmented, and the two flagella have slightly increased in length,
though still uniarticulate. In the last of these stages (see fig. 3) the long apical bristles
of the flagella are lost, and the two sensory appendages of the flagellum, arising originally
from the tip, are now aflixed to a ledge-like projection of the inner edge, near the base.

In the Cyrtopia stages the peduncle (fig. 4) has a somewhat greater similarity to
that of the adult animal, the spine springing from the basal joint being somewhat
reduced in size, and both the flagella considerably elongated and divided into a number
of distinctly defined articulations.

But not tin the last stage described above — the first post-larval stage — do the
antennulse (fig. 5) assume their definitive form, differing only from those of the adult
animal in the dorsal leaflet of the basal joint being still but slightly indicated, and in
the flagella having not yet attained their full length.

The Antennce (figs. 6-8). — The structure of these limbs is much the same throughout
all the Calyptopis and Furcilia stages. They diff"er widely from those in the adult
animal both in form and function, constituting, as they do, very mobile, biramous natatory
organs of much the same appearance as that described above in the larvae of Nyctiphanes,
and strongly reminding one of the second pair of antennae in the Calanoid Copepoda.

In the last Furcilia stage some of the natatory setae are sometimes, however, found
to be obliterated (see fig. 6), though in other respects no difference in the structure of
the organs has yet arisen.

But in the next, or first Cyrtopia stage, these organs (fig. 7) arc seen to have
suddenly undergone a total alteration alike in structure and function, having lost their
great mobility, and assumed a form more in accordance with that of the adult animal.
The basal j)art is shortened and has lost its segmentation, whereas a slender spine has
sprung from the end externally, representing the basal spine of the adult animal. Of

160 THE VOYAGE OF H.M.S. CHALLENGER.

tlic two brauches, originally nearly similar in structure, the outer lias assumed the
character of au oval scale, fringed along its inner edge and apex with a regular series of
slender bristles, whereas the inner branch has retained its cylindrical form, though some-
wliat produced and divided into a biarticulate peduncle, and a non- articulate, naked,
and digitiform, terminal part, forming together the flagellum.

In the next Cyrtopia stage the flagellum becomes still more produced. But not till
the first post-larval stage does it assume (fig. 8) its definitive structure, the peduncle being-
then triarticulate, and the terminal part subdivided into a number of distinctly defined
short articulations, furnished with minute bristles.

Tlie Mandibles (figs. 10-12). — Also these organs exhibit no change whatever through
most of the larval stages, retaining (fig. 10) the peculiar armature of their cutting edges,
as described above in the larva3 of Nyctiphanes, and also the spiniform projection
occurring at the base of the masticatory part anteriorly. Of a palp no trace whatever
can be detected previous to the Cyrtopia stages, when a very small and soft knob-like
projection first apjjears on the outer face of the mandibles, at the base of the masticatory
part. This process becomes, in the second Cyrtopia stage, somewhat more elongate
(see fig. 11), but is still non-articulate and naked. Finally, in the fii'st p)Ost-larval stage,
the palp (see fig. 12) has become considerably produced, and divided into three distinct
articulations, the two outer of which bear each a single bristle. In this and the two
preceding stages, moreover, the peculiar supplementary plate of the cutting edge, described
above in the larvae of Nyctiphanes, and also occurring in the larvse of Euphausia, would
appear to be entirely lost.

The First Pair of Maxillce (figs. 13-15). — The appearance of these maxillte in the
larvai previous to the Cyrtopia stages (fig. 13) is much the same as that described above
in the larvse of Nyctiphanes, with this exception, however, that the palp is distinctly
biarticulate. In the Cyrtopia stages, however, the palp becomes uniarticulate, its two
original joints being fused together (see fig. 14), and at the same time it assumes a
somewhat oval form, still more pronounced in the following stage — the first post-larval
(see fig. 15). In the latter stage, too, the true exoguath makes its appearance,
originating, apart from the larval exognath, in the form of a thin elliptical lamella bearing-
only a single bristle at the tip. The larval exognath, with its four strong setoe, is still
found in this stage beneath the newly formed lamellar exoguath, Ijut in the following
cntii'ely disappears.

The Second Pair of MaxillcB (figs. lG-18). — Also these maxillte exhibit scarcely any
change throughout the true larval stages, their structure (fig. 16) being very similar to
that described above in the larvae of Nyctiphanes. The first perceptible alteration is
observed in the last Cyrtopia stage, when a new setae has developed behind that
affixed to the end of the basal part exteriorly (see fig. 17). In the succeeding stage
(first post-larval) three more setse are added (see fig. 18), constituting, along with the two

REPORT ON THE SCHIZOPODA. 161

others, a regular series along the outer edge of the basal part, which appears here
a little expanded, thus representing the first rudiment of the lamellar exognath. The
terminal joint, or palp, in this stage is now considerably expanded, and assumes a form
more in accordance with that of the adult animal, though still provided with only three
setge. In the following stages, however, the number of setae gradually increases, and
the short spiniform bristles, characteristic of the present species, make their appearance,
only a single one being at first developed.

The Maxillipeds (figs. 19-22). — In the Calyptopis and Furcilia stages these
limbs retain their original structure (see fig. 19) almost unchanged, agreeing precisely
with that of the larvae of Nyctiphanes, as described above. In the last Furcilia stage,
however, a very slight elongation of the endopodite can be traced, and in the first
Cyrtopia stage this part (see fig. 20) has become triarticulate, the middle joint being
rather elongate and exhibiting a slight trace of a median constriction, whereas the
apical joint is very small. In the last Cyrtopia stage the endopodite (see fig. 21) is
still more produced and distinctly four-jointed, and, finally, in the first post-larval stage
this part (see fig. 22) has become quite pediform and composed of five distinctly
defined joints. The exopodite in the same stage shows an incipient division into
two principal parts, viz., the basal and terminal, the division, however, being not yet
fully complete.

The Legs (figs. 23-27). — The first trace of these limbs is found in the first Furcilia
stage, a pair of small simple processes (fig. 23) then appearing just behind the maxilli-
peds. These processes, representing the first pair of legs, rapidly increase and give
origin, at their outer side, to a small lateral knob, the first appearance of the exopod
(see fig. 24). In the intermediate Furcilia stage, represented in PI. XXIX. fig. 6, the
endopod (fig. 25) has already become distinctly articulated and provided with a few
small bristles. Moreover, in this stage the luminous globule, imbedded in the coxal
joint, is faintly seen, as also the first trace of the corresponding gill. In the last
Furcilia stage these legs (fig. 26) are quite pediform, the endopod being rather pro-
duced and five-jointed, and in the Cyrtopia stages (fig. 27) they assume more and
more the structure characteristic of the adult animal, until, in the first post-larval stage,
they merely differ by reason of the somewhat smaller number of marginal bristles.

The second paii- of legs are found in the intermediate Furcilia stage, budding forth
behind the first in precisely the same manner as that pair ; and the following pairs
make their appearance successively in the next stages, until, in the first post-larval stage,
aU the five pairs present in the adult animal are fully developed, the last, however,
being still very small.

The Gills (figs. 28-32). — As previously stated, the first trace of these organs occurs
as early as the intermediate Furcilia stage described above, but merely as incon.spicuous
simple knob-like projections at the bases of the Inidding legs (see fig. 25). In the last

(ZOOL. CHALL. EXP. PART XXXVII. 1885.) Oo 21

162 THE VOYAGE OF H.M.S. CHALLENGER.

Furcilia stage (fig. 28) four pairs of gills have made their appearance, of which
the anterior three are now bifurcate (see also fig. 26), the last pair simple. In the
following stage (first Cyrtopia stage) six pairs may be seen (fig. 29), the three anterior
being still bifurcate, whereas the next pair are very small and knob-like ; and of the
two last paii's, the anterior are bifurcate, the posterior simple. At the base of the
former occurs a rounded expansion, within which a luminous globule has appeared,
and hence these two pmirs are found in reality to represent the two last pairs in the
adult animal. The antepenultimate pair are of covirse not yet developed, nor is any
trace of the corresponding legs as yet perceptible. In the last Cyrtopia stage (fig. 31),
however, aU the gills have developed, the four anterior pairs being bifurcate, the fifth
simple, the penultimate quadripartite, and the last tripartite. Finally, in the first
post-larval stage (fig. 32) the third and fourth pairs have become tripartite, the fifth
bifurcate, and the two last pairs respectively quinque- and sex-partite. During the pro-
gressive growth of the animal the gills gradually acquire a more complex structure,
the two last pairs in j^artieular becoming rapidly larger and more distinctly
arborescent.

Tlie Pleopoda (figs. 33-35). — The development of these limbs does not commence
till the Furcilia stage, and proceeds successively from before backwards. In the
first of these stages a pair of small bud-like processes are seen springing from the
ventral face of the first caudal segment. When isolated and strongly magnified, these
processes (fig. 33) exhibit a somewhat lanceolate form, and have on the inner side a very
small projection — the first trace of the inner plate. In the stage occurring between the
two first Furcilia stages described above, similar bud-like processes successively appear
on the following three caudal segments. In the intermediate Furcilia stage, figured in
PI. XXIX. fig. 6, the penultimate segment has also acquired a similar pair of buds, and
those belonging to the first caudal segment have now attained a more complete develop-
ment (fig. 34), being composed of a distinctly defined basal part and two terminal plates,
the outer of which is much the larger, and furnished with six natatory set^, whereas the
inner is very small, conical in form, and bears a single apical seta only. The other
pleopoda now successively acquire a similar structure, while the anterior pair develop
further (fig. 35), their inner plate becoming more complete, acquiring at first an
additional seta springing from the outer edge, as also a small projection at the inner
edge, representing the secondary lobe occurring in the adult animal. The following
development proceeds successively from liefore backwards, till finally all the pleopoda
have acquired their definite form.

The Tdson (figs. 3G-42). — This part undergoes a constant change during the several
stages of development, being at first very broad and spathulate in form, and becoming
successively narrow until at last it assumes the slender spine-like form characteristic of
the adult animal. This change is also, as will appear in the sequel, accompanied by a

REPOET ON THE SCIIIZOPODA. 163

remarkable altonition in the armature, most of the spiucs observed in the hxrval telson
at length wholly disappearing, and a few only being left to acquire the peculiar form
characteristic of those in the adult animal.

In the earliest Calyptopis stage described above, the telson (fig. 36) is not yet defined
from the last caudal segment. It constitutes a broad spathulate plate, constricted a little
posteriorly to tlie middle, and armed on either side with a strong lateral spine. The end
is somewhat expanded and broadly truncate, and its terminal edge fringed with a row
of thirteen strong ciliated spines. Of these, the median is very small, the three
succeeding ones on either side being somewhat larger and uniform in size. The three
outermost spines on either side, occupying the rounded lateral corners, are much stronger
than the rest, and the middle one by far the largest, projecting considerably beyond the
others.

In the last Cal)'j)topis stage the telson (fig. 37) is distinctly defined from the last
caudal segment by a well-marked suture, and at its base the uropoda have developed.
The form and armature of the telson do not, however, difler materially from those in
the preceding stage.

In the first Fureilia stage the telson (fig. 38) has become somewhat narrower in
proportion to its length, and the median of the terminal spines has attaintnl the size of
those succeeding it on either side, all forming together an uninterrupted row of seven
uniform and comparatively short spines occupying the median part^of the terminal edge.

In the intermediate Fureilia stage the telson (fig. 39) is considerably narrower than
in the preceding stages, though still somewhat expanded towards the end, which has
assumed a broadly rounded form, the middle part, bearing the seven small spines, being
somewhat protruded. Of the three outer spines, the innermost has become remarkably
strong, though still shorter than the middle one, and the cilia at its inner edge are
coarser and more dentiform.

In the last Fureilia stage the telson (fig. 40) is almost linear, being scarcely at aU
expanded at the end. The middle part of the extremity protrudes considerably, being,
however, still truncate at the tip, and bearing the original number of spines (seven),
which are very small and densely crowded together. Of the outer spines, the innermost
has still more increased in size, being almost as long as the middle one and much
thicker, whereas the outermost spine has diminished in size.

In the first Cyxtopia stage the telson (fig. 41) is very narrow, linear, and the
middle part of the extremity juts forth as a conical process, bearing at its narrow
truncate tip only three spines, four of the original ones having disappeared. The inner-
most of the outer spines, on either side, is now very large and sharpened at the inner,
strongly denticulate edge, as also distinctly projecting beyond the others.

In the last Cyrtopia stage the telson (fig. 42) has nearly assumed its definitive
form, being somewhat iucrassate at the base and slightly tapering towards the apex.

1G4 THE VOYAGE OF H.M.S. CHALLENGER.

which juts out as a lanceolate pointed projection, all the original spines affixed to this
part in the earlier stages having disappeared. The three outer spines on either side of
this projection arc still present in this stage, and the innermost of these spines is very
large and has already assumed the form characteristic of the subapical spines in the
adult animal, whereas the outermost is exceedingly small and easily recognised as
representing the posterior pair of dorsal spines in the adult animal.

In the first post-larval stage, finally, the telson has assumed the precise appearance
characteristic of the adult animal, the middle of the exterior spines having been
wholly lost.

Thus, of the spines occurring on the telson in the larva, three pairs only are
retained in the adult animal, viz., the lateral spines, which represent the anterior pair
of dorsal denticles, the outermost, on either side, of the terminal spines, constituting
the posterior pair of dorsal denticles, and the third spine on either side, counted from
the outer corner, which are modified to form the peculiar subapical spines of the adult
animal. All the other spines wholly disappear in the course of the larval development.

The Uropoda (figs. 37-42). — As stated above, these limbs are entirely wanting in
the earliest larval stages (see fig. 36), not appearing till the last Calyptopis stage, when
they are (fig. 37) very small and have only an indistinct mark between the basal part
and the terminal plates, the latter being furnished with but very few bristles proceeding
from their apex ; of the plates, the exterior one is the longer, and has the outer corner
drawn out to a strong spine. In the following stages (figs. 38-40) the uropoda
develop by degrees more fully, the terminal plates increasing in length and becoming
furnished with a greater number of bristles, continued along their inner edge, till in the
first post-larval stage (fig. 42) they have almost attained the aspect characterising those
of the adult animal, though still somewhat shorter in relation to the telson.

The Luminous Apparatus (figs. 9, 25-32). — Of the numerous organs constituting
this peculiar apparatus, those occurring in the eye-pedicles of the adult animal are first
developed. According to the statements of Metschnikoff", even in the Nauplius stage
the peculiar fascicle of glistening fibres, constituting the essential part of these organs,
is distinctly seen on either side of the larval eye, or ocellus, no trace of the compound
eyes being as yet observed. In all the succeeding stages these organs are readily
discerned, imbedded in the base of the developing eyes. The other organs, the true
luminous globules, make their appearance at a much later period, and are not all
developed at the same time, but appear successively. In the intermediate Furcilia
stage (PI. XXIX. fig. 6) only three such globules are developed, viz., the anterior of
the two pairs belonging to the trunk, and the foremost of the odd caudal globules. In
the last Furcilia stage the posterior pair Ijelonging to the trunk have likewise appeared,
though being still but very faintly defined (see fig. 29), as also another of the caudal
globules. The remaining two caudal globules successively ' appear in the following

REPORT ON THE SCHIZOPODA. 105

Cyrtopia stages, and in tlie first post-larval stage all of the globules have been fully
developed.

The Internal Organs (PL XXIX.). — As regards the dcvelopmeut of the iuterual
organs, the following observation may be here added : —

The ganglia of the nervous cord are at first imperfectly defined from one another,
forming merely a continuous ganglionic mass, exhibiting but slight intumescences at
regular intervals. Not till the tail has been fully segmented are the commissures
connecting the caudal ganglia distinctly seen, though at first very short.

The digestive system would not seem to commence performing its functions tUl after
the Metanauplius stage, or when the oral organs have become mobile and armed with
bristles and spines, a considerable supply of food-yolk having been loft within the Ijody
of the Nauplius to be at first absorbed. In the earliest Calyptopis stage, however, the
intestinal tube is distinctly seen traversing the whole length of the body, and, in living
specimens, exhibiting energetic peristaltic movements. Anteriorly, at the junction of the
intestine with the stomach, a well-marked rounded caecum, also present in the adult
animal, is seen protruding above. The liver constitutes at first only two or three simple
cseciform appendages on either side (see PI. XXIX. fig. 1). These appendages become
in the following stages subdivided into short lobes (see fig. 2), which increase gradually in
number, forming at length the compound lobular masses constituting this organ in the
adult animal (see following figures). The anal opening is found in the early Calj^iitopis
stages at the base of the spathulate extremity of the tail (telson), in the form of a
short longitudinal fissure, bounded by two thickened lips (PI. XXX. fig. 36).

The heart, even in the earliest Calyptopis stages (and also in the Metanauplius
stage), can be distinctly seen beneath the posterior part of the carapace, and resembles, at
least as regards form, in every respect that of the adult animal. In living specimens it
may at once be detected by reason of its quick and rhythmical pulsations. Furthermore,
the chief arteries would seem to be developed even in these early stages, as shown by
Professor Claus in his treatise referred to above (page 149).

Development of T/i i/sanojyoda tricuspidata, Milne-Edwards (PI. XXXI. figs. 1-22).

The development of this form difters in certain points distinctly from that of
Nyctiphanes and Euphausia, and the general appearance of the larvae is so very unlike
that of the adult animal, that I certainly should not have been able to refer them to the
above named form, if there had not, fortunately, been in the Challenger collection a
considerable number of specimens in different stages of development, thus connecting the
larval forms with the adult form. The specimen described by Dana as Cyrtopia rostrata
I regard as belonging to this species. In the following pages I purpose describing some
of the most characteristic stages.

166 THE VOYAGE OF H.M.S. CHALLENGER.

Cahjptopis Stages (figs. 1, 2, 7, 13-17). — I have only had the opportunity of examining
two not very well-preserved specimens in these early larval stages, and have figured both.
They were found to represent two successive stages, ajjparently corresponding to the two
last Calyptopis stages, as described above of Nyctiphanes and Eupliausia. The length
is respectively 2 J- and 3| mm.

The form of the body in both specimens (figs. 1, 2) is very slender, especially the
tail. The carapace is rather large, with evenly arched edges, and forms in front a hood-
like expansion, covering the eyes and basal ^Vixta of the antennula?. The tail is
distinctly segmented, but in the smaller specimen (fig. 1) the last segment has not yet
been defined from the telson, whereas in the other (fig. 2) all the segments are
distinct.

The eyes (fig. 7) exhibit a very peculiar form, being oblong-ovate, with the
extremity tapering to an obtuse point, on which occur seven distinctly marked len-
ticular facets of the outer integument. Imbedded within each eye is a dense fascicle
of delicate fibres extending well-nigh in the longitudinal axis, and apparently repre-
senting the luminous organ.

The antennulse and antennge exhibit much the same structure as in the corre-
sponding stages of Nyctiphanes, the former organs consisting in both specimens of a
triarticulate peduncle and two very small uniarticulate flagella ; moreover, in the larger
one, the strong spine arising fi-om the basal joint exteriorly has been developed, whereas
in the other it is stiU wantino-.

The four pairs of ventral (oral) apjDendages (figs. 13-16) also present considerable
resemblance to those in the Calyptopis stages of Nyctiphanes and Euphausia, though
differing in the following particulars : —

The projection jutting out from the mandible (fig. 13) at the base of the masti-
catory part is remarkably large and spiniform, tapering to a very acute point. The
palp, or terminal part, of the first pair of maxillae (fig. 14) consists of a single joint
bearing three bristles only. That of the second pair of maxillte (fig. 15) is exceedingly
small. On the other hand, the exopodite of the maxillipeds (fig. 16) is relatively
larger than in the corresponding stages of Nyctiphanes and Euphausia, projecting con-
siderably beyond the endopodite, and furnished with five strong ciliate setae, exclusive
of a much shorter seta affixed to its base.

The telson (fig. 17) exhibits the usual spathulate form, being conspicuously
expanded towards the apex, which is slightly incurved in the middle, with the lateral
corners evenly rounded off". It is armed with the same number of spines as in the
larvae of Euphausia, viz., two lateral and thirteen terminal, but the spines are slightly
different as regards arrangement and relative size. Thus the lateral spines are
affixed somewhat anteriorly to the middle, not posterior to it, as in the larvae of
Euphausia. Moreover, the terminal spines are rather unequal in size, the median.

REPORT ON THE SCHIZOPOPA. 167

arising from the bottom of the incurvation being very small, whereas the three
following on either side increase in size successively. Of the three outer spines,
occupying the lateral corners, the innermost is by far the largest, projecting consider-
ably beyond the others.

The uropoda, wanting in the smaller specimen, were distinctly developed in the
other (fig. 17), though still rather small.

Furcilia Stages (figs. 3-5, 18, 19). — There are several successive stages in the collec-
tion, of which 1 have figured two, having a length respectively of 4'20 mm. and 5"00 mm.
They all are distinguished by an exceedingly slender form and a distinctly marked
median bend of the tail.

The carapace has lost the hood-like expansion characteristic of the Calyptopis stages,
the frontal margin being deeply emarginate on either side, so as to allow of the eyes
projecting freely, and juts out in the middle as a narrow horizontal rostral projection,
which in the earlier stage (figs. 3, 4) is truncate at the tip. The inferior margins
of the carapace are, moreover, armed posteriorly to the middle with a strong denticle.

The eyes exhibit nearly the same appearance as in the Calyptopis stages, being,
however, a trifle more tumid iu the middle, and also distinctly pedunculated and
mobile. In the latter of the two stages figured here a densely crowded fascicle of visual
elements (crystalline cones), enveloped at the base by a dark pigment, has appeared
within the extremity of the eye (fig. 8), corresponding, as to number, to the seven
lenticular corpuscles mentioned above as occupying the tip of the eye. As will appear
from the following development, this is quite a provisional visual apparatus, the true
cornea not being developed till a much later period.

In the younger of the two specimens figured here (figs. 3, 4) no trace either of the
legs or of the pleopods has yet appeared, the limbs being precisely the same as in the
Calyptopis stages. On the other hand, in the somewhat older specimen represented
(fig. 5), the budding anterior legs, as also the first trace of the gills, may be distinctly seen
behind the maxillipeds. Moreover, on each of the three anterior caudal segments a pair
of pleopoda have appeared, but very small, immobile, and without bristles.

The telson (figs. 18, 19) has become rather narrow, scarcely at all expanded at the
extremity, which is at first rounded ofi" (fig. 18), without any trace of the original median
incurvation. The seven median spines form a continuous row occupying the most
prominent part of the extremity, which becomes gradually more prominent (fig. 19), and
at length juts forth as a median process on either side of which the large innermost one
of the outer spines projects.

Cyrtopia Stage (figs. G, 9, 20, 21).— In this stage the animal has a length of 6| to 7
mm., and already exhibits certain characters indicating its parentage. Thus, the carapace
presents above, at some distance posterior to the rostral projection, a small knob-like
prominence as a trace of the peculiar flattened spine characteristic of the adult animal.

168 THE VOYAGE OF H.M.S. CHALLENGER.

Moreover, the posterior caudal segments are produced, as iu the full-grown animal, at the
middle of the posterior margin into distinct dorsal projections, of which that on the third
segment is the largest. Finally, the first pair of caudal epimera begin to assume their
characteristic form, jutting forth anteriorly as small dentiform projections.

The eves (fig. 9) have acquired a consideraljle dilatation in the middle anteriorly,
and within this dilatation the first fiiint trace of the true cornea, with its visual elements
and ocular pigment, may be seen ; the extremity of the eye being stiU produced into an
obtuse point, containing the provisional visual apparatus described above.

The antennae have lost theii- mobility, as in the corresponding stage of Euphausia,
and are so modified as nearly to agree in their structure wdth those of the adult animal,
the two original natatory Ijranches having respectively been transformed into the scale
and the fiagellum.

Four pairs of legs have developed, and the gills may be distinctly seen along the
sides of the trunk beneath the carapace, increasing in size posteriorlj^ the anterior pairs
being still only bifurcate.

On the tail, all the pleopoda have been fully developed and adapted for swimming.
Also the luminous gloliules are now all well defined.

The telson has acquired its characteristic slender form, and the largest of the terminal
spines (see fig. 20) are easily recognised as representing the subapical spines of the adult
animal. The median part of the apex is considerably produced, and its tip is not, as
in the former stages, truncate, but juts out us an acute angle. The two outermost spines
on each side are still unchanged. In one of the following stages (fig. 21) one pair of
the latter has withdrawn to the dorsal face of the telson, constituting the posterior pair
of dorsal denticles of the adult animal.

Post-Larval Stages (figs. 10-12, 22). — In these stages the animal can easily be
recognised as a young Thysanopoda tricuspidata, exhibiting, as it does, all the essential
characteristics distinctive of that species. It still, however, retains a peculiar remnant of
its larval existence. For when viewed from above (fig. 10) the eyes are found to exhibit a
most remarkable form, unlike that of the adult animal, being drawn out at the exterior
side of the cornea to amamillar projection, at the tip of which the seven lenticular facets,
mentioned above as occurring in the larvae, form a perfectly circular area, one of the
lenses occupying the centre and the other six being placed in a regular circle around
it (see also figs. 11, 12). Within this projection the original fascicle of crystalline cones
appears with great distinctness, as also the dark pigment deposited at their base. On
the other hand, the true cornea, though considerably expanded, is still very imperfectly
developed, its areolation being indistinctly marked, and the pigment having a rather
diff'use character. In the foUowing stages this part, however, becomes gradually more
fully developed, while the mamillar projection is reduced in size and finally disappears
altogether.

REPORT ON THE SC'HIZUPODA. 109

The telson assumes, even iu the first of the post-larval stages, the form cluiracteristic
of the adult animal, the apex (fig. 22) l^eiug produced into an acuminate point, armed on
either side with three small denticles — the original terminal spines. Moreover, the outer
spine, occurring in the last Cyrtopia stage next to the subapical spines, has entirely
disappeared.

Development of Nematoscelis rostrata, G. 0. Sars (PI. XXXI. figs. 23-29).

The earlier larval stages of this form would not seem to exhibit any marked
peculiarities, and hence I shall only describe three of the later stages, in which the
characters of the genus are first discerned. Two of these are Furcilia stages, the third
a Cyrtopia stage.

Furcilia Stages (figs. 23, 24, 26-28).— The form of the body in these stages, which
measure respectively 3^ mm. and 4 mm. in length, is far from being so slender as in the
corresponding stages of Thysanopoda tricuspjidata, resembling in this respect more closely
the Furcilia stages of Euphausia.

The carapace has on either side a very strong lateral denticle, projecting from the
inferior margin posteriorly to the middle, and is als(j distinguished by a conspicuous
rounded crest, rising from about the middle of the dorsal face. The rostral projection is
very large, horizontal and sharply pointed, though broad and flattened at the base, more
especially in the earlier stage.

Of legs, two pairs have made their appearance, being, however, in the earlier of the
two stages (figs. 23, 26) still very imperfect as to structure, non-articulate, and without
bristles. But even in this rudimentary state the peculiar modification of the first pair,
so characteristic of the genus, is distinctly recalled, the corresponding buds (fig. 26) being
remarkably massive, and exhibiting a most conspicuous S-shaped flexure. In the later
stage (fig. 24) both of the two anterior pairs of legs have become articulated, and the
first pair now very clearly present the peculiar structure characteristic of the genus
Nematoscelis, though they are as yet far from having attained their fuU length. In this
stage also some of the gills are seen budding forth behind these legs.

Of the pleopoda, four pairs only have been formed in the earlier of the two stages
(fig. 23), and of these the first pair only are difi"ereutiated into a basal part and terminal
plates, whereas the other three still represent merely simple bud-like processes. In the
later stage (fig. 24), on the other hand, all the pleopoda have appeared, and only the
last pair retain their original bud-like character, whereas the other pairs are fuUy
developed and adapted for swimming.

The telson iu the earlier stage (fig. 27) is still rather broad, and slightly expanded at
the apex, with a pair of lateral spines about the middle of its length. The number of
terminal spines is that usually met with, viz., thirteen, seven of which form a continuous

(ZOOL. CHALL. EXP. PART XXXVII. — 1885.) Oo 22

170 THE VOYAGE OF H.M.S. CHALLENGER.

series along the aliruptly tnincatc middle pnrt, wliercas the six others are arranged, three
on eitlier side, along the obliquely rounded lateral corners. Of the latter, the innermost
is by far the largest. In the later stage, the telson has become considerably narrower,
and the middle part of the apex (fig. 28) has begun to jut forth as a still rather broad
projection, truncate at the tip.

Cyrtopia Stage (figs. 2.5, 29). — The transformation of the antennae clearly distinguishes
this stage from the two former as a true Cyrtopia. The animal has now attained a
length of 4-| mm., and may easily be recognised as a young Nematoscelis rostrata. The
first pair of legs are considerably elongated and slender, having nearly attained the
structure characteristic of the adult animal, and the gills are also more fully developed.
All the pleopoda have assumed their definitive form, and the luminous apparatus would
also seem to be distinctly developed. The telson closely resembles in form that of the
adult animal, but still retains some of the larval sj^ines. The middle projection of its
extremity (fig. 29) is considerably produced, but narrowly truncate at the tip ; and of
the seven original spines, three only remain. Of the three outer spines, the innermost
on either side is much larger than the others, and has assumed the character of the
subapical spines. In a succeeding stage, the outermost on either side is withdrawn to
the dorsal face of the telson, thus constituting the posterior pair of the dorsal denticles
of the adult animal, whereas the intermediate spine has altogether disappeared.

Larval Stage of Eup)hausia sji. (?).

First Furcilia Stage (PI. XXXI. figs. 30, 31). — I give a figure of this larva, not only
because it exhibits an unusual size and a rather peculiar aspect, but also because another
stage of precisely the same form has been described at a much earlier date, without,
however, having been at that time recognised as a larva of Eiiphausia.

In the second ])iwt of his researches on the structure and development of the
Arthropoda,^ Professor Dohrn has given figures and descriptions of several very remark-
able larval forms,^ of which that figured in plate 30, fig. 54 undoubtedly represents a
Calyptopis stage of precisely the same form as that treated of here. This larva was met
with in the Indian Ocean, and regarded by Professor Dohrn — though with some reservation
— as a Peueuszoea. That this assumption is erroneous, and that the larva in question
should be comprised under the Euphausiidse, I feel no doubt whatever in asserting ; and,
moreover, I think there are reasons for assuming both these larvje to belong to a large-
sized species of the genus Euphausia, perhaps that briefly mentioned by the late Dr. v.

' Zeitschr.f. wiss. ZooL, Bd. xxi., p. 35G, 1871.

* I take the present opportunity of stating my conviction that the forms described by the said author as Cerataspis
monstruosa, Gray, and Ceratcspis lonijircmis, n. sp., and considered as adult animals belonginf; to the Schizopod tribe,
are both of them larvaj in the last stage (Mysis stage) of some large forms of Macrura of the Homaroid group.

REPORT ON THE SCHIZOPODA. 171

Willemoes-Suhm under tlie name of Euphausia simplex, but unfortunately wanting in
the collection.

What distinguishes these larvae at the first glance is the very peculiar armature
of the free edges of the carapace, which are coarsely and elegantly denticulate in a
regular pectiniform manner, the denticulation being quite continuous all round in
the Calyptopis stage described by Dohrn, whereas in the Furcilia stage represented
here it is interrupted by the lateral emarginations of the frontal margin, from wliich
the eyes project.

The solitary specimen in the collection (fig. 30) has a length of nearly 5 mm., and
evidently corresponds, as regards the development of the limbs, to the first Furcilia
stage of Euphausia peUvcida (PI. XXIX. figs. 4, 5), from which, however, it differs, not
only in its much larger size and the above-mentioned peculiar armature of the carapace,
but in some other points to be set forth in the sequel.

The carapace is comparatively very large and tumid, and has the inferior margins
strongly arched in the posterior part and somewhat incurved anteriorly to the middle, as
also terminating anteriorly in an acutely produced angle. Posteriorly, it juts forth in the
middle as a rather strong, spine-like projection, and is, moreover, provided in the middle
of the dorsal face with a distinctly marked rounded crest. The frontal plate is very large
and broadly rounded at the extremity, and coarsely denticulate along the terminal edge,
the denticles being somewhat larger than those occurring along the inferior margins of
the carapace.

The tail is comparatively slender, and has the edges of the rounded epimera finely
serrate. The third segment juts out posteriorly as a .small but well-defined dorsal
projection. The last segment is but little longer than the preceding, and quite smooth.

The eyes are rather large and projecting, of a slender clavate form, with the cornese
comparatively small.

Of limbs, the antennulse, antennae, mandibles, two pairs of maxillae, and the
maxillipeds are distinctly developed, exhibiting, it would seem, a structure closely
resembling that in the corresponding stage of Exiphausia pellucida. In addition, as in
that stage, the first trace of the anterior pair of legs and of the first pair of pleopoda has
appeared, both having as yet merely the form of small bud-like processes.

The telson (fig. 31) is very large, almost equalling in length the three preceding
segments taken together, and gradually expanding towards the apex, which is broadly
truncate and slightly emargiuate in the middle. The number of spines is as usual
fifteen ; meanwhile both the lateral and three outer on each side of the terminal ones arc
remarkably large and spinulose at the edges, whereas the seven median are very small,
especially the middle one, which is, moreover, quite smooth. The lateral spines are
placed at the last third of the length of the telson ; and of the three outer spines of the
terminal edge, the middle one is much the largest, projecting far beyond the rest.

172 THE VOYAGE OF H.M.S. CHALLENGER.

The uropoda (fig. 31) are still rather small, but have their basal part and terminal
plates well defined, the latter exhibiting a few slender marginal bristles. The outer
plates arc highly distinguished by the remarkable length of the spine jutting out from
the outer corner ; moreover, this spine is finely denticulate along the inner edge.

Habitat. — The larva described above was taken December 24, 1873, in the Southern
Ocean, off Prince Edward Island.

Family 4. Mysid.e.

This family, the lowest in rank among the Schizopoda, comprises both littoral and
pelagic forms, as also true deep-sea animals. In none of them is the slightest trace of
true gills to be observed, and they are thereby very sharply defined from the three
preceding families of Schizopoda, in which the gills are invariably well developed. In
some forms, however, a peculiar folding of the integument, covered by the free parts of
the carapace, can be discerned, and this structure may possibly stand in some relation
to the respiratory function, though scarcely corresponding morphologically to the true
gills in other Podoplithalmia. I first called attention to this peculiar structure as
early as the year 1867, when describing the fresh- water variety of Mysis ocidata,
Fabr. {Mysis relicta, Loven),^ and shall in the present Eeport describe a similar
structure in the large deep-sea Mysidan, Boreomysis scyphoiys, G. 0. Sars. Another
appendage, peculiar to the males only, and issuing from the base of the inner branch
of the pleopoda, may perhaps be also regarded as subservient to respiration. More
especially in the males of the genus Siriella, Dana (Cynthia, Thompson), do these
appendages present an appearance that strongly recalls that of true gills.

As a character common alike to all Mysidans, and sharply distinguishing them
from other Schizopoda, may be mentioned the rudimentary state of the caudal limbs in
the females, forming, as they do, very small setifei'ous lamellse that have no relation
whatever to locomotion, and thus have little or no claim to the term " pleopoda."
This, in some genera, as Mysis, Heteromysis, Mysidella, also applies to the males.
But in most of the genera the caudal limbs in the males are modified so as to assume
the character of true natatory organs, being constructed in a manner similar to the
pleopoda in the Lophogastridse and Eucopiidte.

The Mysidse comprise numerous genera, most of which are met with in the Northern
Ocean, and some of the species, as Mysis oculata, Fabr., are at times found crowded
together in enormous shoals, thus serving as food for whales and other large vertebrates.

The Challenger collection comprises fifteen species of Mysidse, belonging to eight
g.?nera, one of which is new.

' Histoire naturcUe des Crustaces d'eau douce de Norv^ge, pt. i.

REPORT ON THE SCHIZOPODA.

173

The following is a synopsis of the genera represented in the collection : —

Number of
incubatory

lamellae,
composing -|
marsupial

pouch in

female,

seven
pairs.
Male

greatly differing from female, having mandibular
palp and gnathopoda remarkably modified,

differing from female in the usual manner, chiefly
as regards the structure of the caudal limbs,

two

pairs

only,
with a

rudi- \
ment of
a third

pair.

Eyes

,eniiiiial

Legs

imperfectly [ "''^J',"/'''°"°' '"'^' '^ '^'''""^ '"'
developed, I ' ' '

remarkably slender, filiform, without
any terminal claw,

non-subdivided or only
bi-articulate, terminal
claw very strong.

of the usual

structure.

Caudal

limbs in

male

natatory.

Propodal

joint of

legs

sub-
divided

into
three or

more
articu-
lations.

An-
tennal

scale

remarkably
small,

lanceolate, se-
tose on both
edges,

obliquely trun-
cate at apex,
outer edge
smooth,

rudimentary as in female,

Pelaloph thalm iis, Suhni.
Boreomysis, G. 0. Sars.
Amhhjops, G. 0. Sars.
Pseudomma, G. 0. Sars.

Siridla, Dana.
Anchialus, Kroyer.

Mijsldoims, G. 0. Sars.

Euchcetomera, G .0. Sars.
Hetewmysis, Smith.

Genus 1. Petalophthalmus, Willcmocs-Suhm, 1879.
Petaloplithahntis, Suhm, Trans. Linn. Soc. Lond., scr. 2, vol. i.

Generic Characters. — Female exhibiting the usual Mysidau appearance ; male very
dissimilar, with mandibular palps prodigiously developed, and some of the limbs of the
trunk also remarkably modified. Eyes in l)oth sexes leaf-like, without any visual
elements or pigment. Antennular peduncle greatly elongate in male, and without the
usual hirsute lobe. Antennal scale lanceolate and setose on Ijoth edges. Gnathopoda in
male very strong, subcheliform. Marsupial pouch in female composed of seven pairs of
incubatory lamellae. Caudal limbs of male scarcely natatory, inner branch simple, naked,
styliform, outer non-articulate, slightly dilated in the middle, and having an oblique
series of delicate bristles. Telson with apex entire, not incised in the middle. Outer
plates of uropoda distinctly jointed at apex.

Remarks. — The remarkable form on which the above characterised genus has been
based, exhibits, in the female, some affinity to the genus Boreomysis, G. 0. Sars, the
marsupial pouch being, as in that genus, composed of seven pairs of incubatory lamellaj,
and the structure of the legs somewhat similar. Nevertheless, the very striking appear-

174 THE VOYAGE OF H.M.S. CHALLENGER.

ance of tlie male at once distinguishes this genus from all other known Mysidans, the
sexual characters being quite anomalous and differing from what is usually met with in
this fomily. Moreover, the structure of the antennal scale and of the telson, as also that
of the outer plates of the uropoda, would seem to afford well-marked characters, distin-
guishing this genus from the genus Boreomysls. As regards the imperfect development
of the eyes, which has suggested the genei'ic name, that character is also found in one of
the species belonging to the above mentioned genus, viz., in Boreomysis scyphops,
G. 0. Sars, to be described in the sequel.

42. Petaloplithahnus armiger, Willemoes-Suhm (PI. XXXII. figs. 1-9).

Petalophthalmus armiger, Suhra, Trans. Linn. Soc. Loud., ser. 2, vol. i. p. 40, pi. viii.

Specific Characters. — Male : Body rather slender, well-nigh cylindrical in form.
Carapace remarkably small and not nearly covering whole of trunk, two segments of
which are entirely exposed ; cervical sulcus well marked ; frontal margin forming, in the
middle, only a very small projection ; antero-lateral corners narrowly rounded. Eyes
forming two very thin oval lamellfe, suj)ported on short pedicles. Antennular peduncle
exceedingly slender, with basal joint longer than the two others taken together, fiagella
shorter than peduncle, subequal. Antennal scale narrow, lanceolate, projecting but
slightly beyond basal joint of antennulse ; fiagellum imperfectly developed, shorter than
scale, biarticulate. Mandibular palp projecting beyond antennular peduncle, last joint
reflexed and armed with seven strong spines. Maxillipeds short and thick, without
exopodite, meral joint exj)anded interiorly to a linguiform lobe, terminal joint unguiform.
Gnathopoda of a structure similar to maxillipeds, but much larger. The three anterior
pairs of legs with last joint densely hirsute ; remaining pairs very slender, with terminal
part not subdivided, and having a distinct but feeble claw. Telson oblongo-quadrangular,
apex broadly truncate, jutting out in the middle as a short dentiform projection, and
having on either side five strong spines ; lateral edges finely denticulate in the outer half.
Terminal joint of outer plates of uropoda very sharply defined, linguiform. Length, 40 mm.

Remarhs. — Of this interesting form I have only had opportunity of examining a
single male specimen, apparently that described by the late Dr. v. Willemoes-Suhm.
That author has also described the female ; but the specimen from which his descrip-
tion was drawn up has unfortunately been lost. To judge from the figures given, it
would seem to have presented a far less deviating appearance, resembling rather the
species of the genus Boreomysis.

Description of the Male.- — The specimen examined by me, which apparently is full-
grown, measures 40 mm. in length.

The form of the body (see PI. XXXII. fig. 1) is very slender and well-nigh cylindrical,
without exhibiting any sharp demarcation between the anterior and posterior divisions.

REPORT ON THE SCHIZOFODA. 175

The carapace is remarkably small, so as to cover only the anterior part of the trunk,
whereas the two posterior segments of the latter are exposed behind it around the whole
of their circumference. Moreover, the lateral wings of the carapace, in the specimen
examined, were greatly inflected or doubled over, and thus the lateral paiis of the two
preceding segments also appear uncovered inferiorly. The carapace exhibits a well-
marked cervical sulcus, behind wliicli the linguiform dorsal area is distinctly seen. The
frontal margin is truncate, with but a very small dentiform projection in the middle (see
fig. 2) as a rudiment of the rostrum. The antero-latcral corners of the carapace are
narrowly rounded.

The caudal segments are simple cylindrical, without any trace of epimera, the anterior
ones differing but slightly in size and appearance from the two posterior segments of the
trunk. The last segment, on the other hand, is rather elongate, about as long as the tAvo
preceding ones taken together.

The eyes (fig. 3) are cj^uite rudimentary, without any trace either of pigment or visual
elements, constituting merely two thin and pellucid lomellfe, of an oblong form, and
mounted on very short and narrow pedicles. They would seem to a certain extent
movable, and, in the specimen examined, were directed upwards, with their inner faces
parallel to each other and to the axis of the body.

The antennular peduncle (see figs. 1, 2) is very slender and elongate, nearly^
ecjualling the carapace in length, and has the basal joint longer than both the others,
taken together. The last joint is rather small, and does not exhibit any trace of the
hirsute lobe, usually met with in male Mysidans. The fiagella are shorter than the
peduncle, well-nigh uniform in structure and length, and composed of several short
articulations.

The antennal scale (figs. 1, 2, 4) projects but slightly beyond the basal joint of the
antennulse, and exhibits a very narrow lanceolate form, the edges being densely setiferous
all round. The tiagellum is most imperfectly developed, and totally wants the terminal
part, constituting, as it does, merely a short biarticulate stem, corresponding to the
basal portion or peduncle in other Mysidans. This stem scarcely reaches to the tip of
the scale, and is provided with a dense tuft of apical bristles.

The mandibular palps being, according to the statement of the late Dr. v. Willemoes-
Suhm, of quite normal appearance in the female, exhibit in the male (see fig. 1) a truly
remarkable development, jjrojecting, as they do, in the form of a pair of very powerful
limbs far beyond the antennular peduncles. Their middle joint is by far the largest and
strongly muscular, and also furnished along the lower edge with numerous tufts of small
bristles. The last joint is sharply reflexed, forming along with the preceding joint a
geniculate bend, and is armed with seven strong unguiform spines, three of which spring
from the apex, and two from each of the edges. These limbs serve in all probabilitj- as
powerful prehensile organs, by the aid of which the male cla.';ps the female dui'ing

176 THE VOYAGE OF H.M.S. CHALLENGER.

copulation ; l)ut in no other Crustaceans lias a similar modification of these limbs ever
been observed.

As regards the structure of the mandibles themselves, and the maxillae, we cannot of
course give any reliable information, since these organs do not admit of being examined
in the solitary specimen before us. In the female, their structure would seem, to judge
from the description given by the late Dr. v. Willemoes-Suhm, to be on the whole quite
normal.

The maxillipeds (fig. 6) are short and thickset in structure, without any trace of the
usual exopodite, and want also, it would seem, the epipodite. They consist, however, of
the usual number of joints, which together form a strongly curved stem. The meral
joint is expanded interiorly to a rather large linguiform lobe, against which the outer
part of the maxilliped admits of being impinged. The terminal joint has the form of a
strong claw.

The gnathopoda (or first ^mv of legs) exhibit a structure much resembling that of
the maxillipeds, though considerably larger and having the meral lobe comparatively
more powerfully developed. No trace of an exopod can be detected, and the aspect
of these limbs is, on the whole, very dissimilar from that of other Mysidans. In the
female, however, to judge from the figure given by the late Dr. v. Willemoes-Suhm, they
would not seem to exhibit any marked difference from that usually met with in
Mysidans, and hence the peculiar modification both of these limbs and the maxillipeds
in the male must certainly stand in some relation to the act of copulation.

Of the true legs, the two anterior pairs had been broken ofi" in the specimen examined,
their basal parts only, with the corresponding exopods, remaining intact. The third
pair (see fig. 1) exhibit a form somewhat resembling that of the gnathopoda in other
Mysidans, the terminal joint being not unguiform but obtuse and densely hirsute ; and
the two anterior pairs may, very probably, also have exhibited a similar appearance. The
three remaining pairs of legs are exceedingly slender, and have the terminal part,
or propodal joint, not subdivided, as in most other Mysidans, and tlie last joint modified
to a distinct, though very feeble claw.

The caudal limbs (fig. 7) are not, as usual in the males of most other Mysidans,
modified to natatory organs, or pleopoda, though somewhat dissimilar in structure from
those in the female. They consist of a rather feeble basal part and two very unequal
terminal branches. The outer of these forms merely a slender cylindrical simple
appendage, without any armature whatever, whereas the inner branch is rather large and
somewhat expanded in the middle, having there an obliquely transverse series of very
deUcate bristles, the terminal part tapering somewhat and furnished with two bunches of
short bristles. Any distinct articulation cannot be detected in either of the branches.

The telson (fig. 8) is a trifle shorter than the last segment, and exhibits the form
of an oblongo-quadrangular plate, being everywhere about of the same breadth and

REPORT ON THE SCHIZOPODA. 177

broadly truncate at the apex. The lateral edges are in the outer half finely denticulate,
and the apical edge juts forth in the middle as a short dentifoi-ni projection, on (ntlier
side of which are affixed five strong spines (see fig. 9).

The uropoda (see fig. 8) have the inner plates of about tlie same length as the
telson and narrowly lanceolate in form, whereas the outer plates are considerably larger,
and clearly distinguished by the outer linguiforra part being marked off" from the plate
by a very distinct articulation, a feature not observed in any other known form of
Mysidans. The outer edge of the plate is quite smooth, and terminates as a distinctly
projecting corner bearing a short spine, whereas the terminal articulation and also the
whole inner edge of the plate is fringed with a dense row of ciliate setae.

Habitat. — The above described specimen was taken in the Tropical Atlantic, at a
very considerable depth. Locality:. Station 104, August 23, 1873; lat. 2' 25' N.,
long. 20° 1' W.; depth, 2500 fathoms ; Globigerina ooze ; bottom temperature, 36°-6.

Genus 2. Boreomysis, G. 0. Sars, 1869.
Boreomysis, G. O. Sars, UndersogeLser over Christianiafjordens Dybvandsfauna.

Generic Characters. — Carapace rather large, covering most of trunk, antero-lateral
comers produced, lobiform. Tail slender, cylindrical, with last segment longest.
Antennular peduncle comparatively robust, with male appendage very short, tuber-
culiform ; outer flagellum more or less distinctly expanded at base. Anteniial scale
elongate, sublinear ; outer edge smooth, terminating in a dentiform projection. Last
joint of mandibular palp narrowly oblong. Second pair of maxillae with inner expan-
sion of basal part very broad, terminal joint oval, with some of the bristles recurved.
Gnathopoda elongate, with terminal joint very mol)ile and densely hirsute. Legs
rather slender, subequal, with propodal joint subdivided into two or three articulations,
terminal joint unguiform. Marsupial pouch in female composed of seven pairs of
incubatory lamellae. Caudal limbs in male all natatory, with very elongate branches.
Telson large, deeply incised at apex. Outer plate of uropoda with a ledge-like pro-
minence in front of the middle exteriorly, bearing two small denticles. Auditory
apparatus at base of inner plate rudimentary.

Remarks. — This genus is distinguished from most other Mysidans bv havini'- the
marsupial pouch of the female composed of seven pairs of incubatory lamellae. In this
character it agrees only with the preceding genus, from which, however, it may be
easily recognised by a deviating structure of the antennular peduncle, the' antennal
scale, and the caudal fan, besides the male sexual characters, which in the present
genus are quite normal, whereas in the former they are very peculiar and
anomalous.

The typical species is Boreomysis arctica (Kroyer), first met with in the Arctic Sea,

(ZOOL. CHALL. EXP. PART xxxvu. — 188.5.) Oo 23

178 THE VOYAGE OF H.M.S. CHALLENGER.

off Greenland, and also occurring along the coasts of Norway, where two other species,
Boreomysis tridens, G. 0. Sars, and Boreomysis megalops, G. 0. Sars, have been also
observed. Moreover, on the Norwegian North Atlantic Expedition two large species
were taken, Boreomysis nohilis, G. 0. Sars, and Boreomysis scyphops, G. 0. Sars, the
latter of which is also represented in the Challenger collection. Finally, there are two
additional species from the Challenger Expedition, to be described further on. The total
number of species thus amounts to seven. All are true deep-sea forms, the animals
descending to very considerable depths, and having never been met with in shallow
water.

The following is a synopsis of the three Challenger species : —

imperfectly developed, calyciform, without pigment or visual elements, . B. scyphops, G. 0. Sars.

Eyes

of the usual
structure,

short and thick, almost circular, with cornea greatly expanded.

Frontal margin obtusely rounded, . . . B. ohtusata, G. 0. Sars.

narrow, almost fusiform, with cornea very small. Frontal

margin with a small pointed projection in the middle, . B. microps, G. O. Sars.

43. Boreomysis scyphops, G. 0. Sars (PL XXXII. figs. 10-20).

PetalojMhalmus inermis, Suhm MS.

Boreomysis scyphops, G. O. Sars, Crustacea et Pycnogonida nova in itinere 2do et 3tio

Expeditionis Norvegicse anno 1877-78 collecta, No. 3.
Boreomysis scyphops, G. O. Sars, The Norwegian North Atlantic Expedition, 1876-1878,

Crustacea, i. p. 56, pi. vi.

Specific Characters. — Frontal part of carapace without any distinct rostrum,
projecting but slightly in the middle ; antero -lateral lobes obtuse at apex. Eyes without
pigment or visual elements, constituting two pedunculated concave, or well-nigh calyciform
lamellae, placed vertically. Antennular peduncle comparatively smaller than in the other
species, and of more noi-mal form. Antennal scale rather elongate, about twice as long
as antennular peduncle, slightly tapering, denticle of outer corner somewhat projecting.
Propodal joint of legs subdivided into two articulations only ; exopods remarkably
elongate, with terminal part composed of numerous articulations. Telson almost
equalling in length the two preceding segments taken together, outer part slightly
tapering, and fringed with numerous small denticles, apical incision narrow, occupying
nearly one-fourth of the length of telson. Inner plate of urojioda reaching tip of telson,
outer plate much larger. " Colour a uniform pale red. Length reaching 85 mm.

Remarhs. — This gigantic Mysidan was first met with on the Challenger Expedition
in the subantarctic region of the Southern Ocean, and has been briefly recorded by the
late Dr. v. Willemoes-Suhm under the provisional name of Petalophthalmus inermis.
Subsequently the same form was obtained on the Norwegian North Atlantic Expedition

REPORT ON THE SOHIZOPODA. 179

in the Arctic Sea, and has been more fully described by the author under the name of
Boreomysis scyphops. Although the former appellation has without a doubt claim to
priority, I have seen fit to retain that proposed by myself, for the following reasons : —
First, it is obvious that the said form cannot properly be comprised within the same
genus as the preceding anomalous Mysidan, the only characters peculiar to both being
merely the rudimentary condition of the eyes, whereas in all other respects it agrees much
more closely with the species of the genus Boreomysis, to which of course it should
rightly be referred. Secondly, this admitted, the specific name inermis would be quite
inappropriate, referring, as it does, to the absence in the male of similar prehensile organs
as in Petalophthalmus armiger, such a peculiar prehensile apparatus being never found
in any species of the genus Boreomysis. Thirdly, no description of this form has been
given by the late Dr. v. Wdlemoes-Suhm, by whom the animal is only briefly recorded
as a new species.

Although a full account of the present interesting Mysidan, with figures representing
both sexes, has been given in the Report on the Crustacea collected on the Norwegian
North Atlantic Expedition just published, I have deemed it advisable to append the
following somewhat modified description of the Challenger form.

Description. — Most of the specimens in the collection are females, and of the two male
specimens found, none is yet fully developed. The largest female specimen measures about
85 mm. in length from the tip of the antennal scale to that of the uropod, or still
somewhat more than the arctic specimens collected on the Norwegian Expedition.

The form of the body (see PI. XXXII. fig. 10) is somewhat robust, with the anterior
and posterior divisions pretty well defined.

The carapace is rather large, covering the whole of the trunk, except a small part of
the last segment, which appears exposed above. Moreover, the rounded lateral parts or
wings of the carapace slightly overlap the first caudal segment. The cervical sulcus is
very distinctly defined, marking off" the cephalic section or frontal part of the carapace.
The latter portion is evenly arched above, without any keel, and juts forth anteriorly in
the middle as a slightly projecting angle. At the sides, the frontal margin forms, as in
the other species, a deep emargination almost wholly exposing the basal part of the
antennae (see figs. 10, 11). Beneath this emargination each of the antero-lateral corners
projects as a liuguiform lobe, obtuse at the tip. The dorsal area is seen extending
posteriorly behind the cervical sulcus as a narrow linguiform space, reaching to about the
posterior third of the length of the carapace.

On removing the free parts of the carapace (see fig. 11) ail the segments of the trunk
are visible, as in the Lophogastridse and Eucopiidaj, distinctly defined in their whole
circumference, though densely crowded dorsally, in such a manner that only the last
segment has the dorsal face of any considerable extent, whereas the others are extremely
narrow, almost riband-shaped in that part. Laterally, each of the six anterior segments

180 THE VOYAGE OF H.M.S. CHALLENGER.

produce a peculiar folding of their integument, increasing in breadth inferiorly and
exhibitintr here as it were an imbricate appearance. These peculiar cuticular folds, first
noticed by the author when describing the fresh-water variety of Mysis oculata, Fabr.
{Mysis relicta, Loven), occur more or less distinctly developed in all Mysidans, and may
to some extent compensate for the absence of true gills, these parts being constantly bathed
by the current of water flowing beneath the free parts of the carapace, and chiefly
produced by the oscillatory movements of the epipodite of the maxilliped that projects
within the branchial cavity anteriorly.

The caudal segments are perfectly cylindrical, without the slightest trace of epimera,
and somewhat less in breadth than the anterior part of the carapace. The last segment
is much the longest, about twice as long as the preceding.

The eyes (fig. 13) exhibit nearly the same imperfect structure as in the genus Petaloph-
thahnus, lacking, as they do, every trace of pigment and visual elements, and constituting
merely simple lamellar or petal oid expansions, mounted in a vertical position on short
pedicles. As to form, they differ somewhat from those in Petalophthalmus armiger, being
distinctly hollowed on the outer face, or well-nigh calyciform, their aspect being almost
as if the true eye-globe or cornea were extirpated, and only the skin of the pedicle left.
Anteriorly they form a slight angular projection, being for the rest of a somewhat irregular
oval form.

The antennular peduncle (see figs. 10-12) is comparatively smaller than in the other
species of the genus, and has also a more regular cylindrical foi'm, the second joint being
simple and not discoidal or cup-shaped. The outer flagellum forms only a slightly
defined expansion at the base.

The antennal scale (see fig. 12) is rather large, almost twice as long as the antennular
peduncle, tapering toward the apex, which is obliquely rounded, w'ith the outer corner
somewhat projecting and dentiform.

The mandiljles (fig. 14) exhibit the structure characteristic of the genus, the palp
being rather elongate, with its terminal joint narrowly oblong.

The first pair of maxilhe (fig. 15) are also c_[uite normal in structure and agree as
regards all essential features with those organs in the other species of the genus.

The second pair of maxillas (fig. 16) have the basal part rather large, forming inwards
a slightly arched and sharp border, densely beset with delicate curving bristles. There
are, as usual, three masticatory lobes densely crowded together at the inner corner of the
basal part. The exognath is but of moderate size and elliptical in form, fringed with
delicate plumose setae along the outer edge. The terminal joint of the palp is oblong,
and has the bristles of the outer edge recurved, as in the other species of the genus.

The maxillipeds (fig. 17) are not particularly powerful in development, and have the
basal part of about the same length as the terminal or palp, projecting inward as a
narrow, linguiform masticatory lobe. Of the joints of the palp the antepenultimate

REPORT ON THE SCHIZOPODA, 181

(carpal) is the longest ; the terminal joint is conically pointed antl provided at the tip
with a strong unguiform spine. The exopodite (see fig. 11) is very fully developed, in
the same manner as tlic true exopods. The epipodite is narrowly lanceolate or almost
falciform, and al)out as long as the basal part.

The first pair of legs (fig. 18) differ, as in other Mysidans, conspicuously from the
rest, being modified to serve as true gnathopnda. They are rather elongate, with the
carpal joint longest. The propodal joint, which, as a rule, forms along with the foraier
a sharp geniculate bend, is somewhat dilated towards the end, exliibiting there, at the
inner edge, a slight incurvation to receive the terminal joint when bent in. The latter is
very small and densel}^ hirsute, as also exceedingly mobile. The exopod is remarkably
elongate, its terminal part consisting of a great number of short setiferous articulations.

The true legs are all of them uniform in appearance, somewhat slender and densely
setiferous, more especially along their inner edge. The pro^xtdal joint (see fig. 19) is in
all subdivided only into two articulations of unequal size, the proximal more than twice
the length of the distal, and furnished with dense fascicles of setae. The terminal joint
has the form of a slender claw. The exopod is very greatly developed, and of precisely
the same structure as in the gnathopoda.

The marsujiial pouch of the female is composed, as in the other species of this genus,
of seven pairs of incubatory lamellae, originating from the bases of the gnathopoda (see
fig. 18) and all of the true legs ; they increase successively in size from before backwards
(see fig. 11).

The telson (see fig. 20) is comparatively large, attaining almost the length of the two
preceding segments taken together, and has the form of an oblong lamella, slightly
channelled above and somewhat tapering in its outer part, which is edged with numerous
small denticles of unecjual size. The apex is deejjly incised, the incision being very
narrow, and occupying almost one-fourth of the length of the telson. The terminal lobes,
limiting the incision, are obtusely pointed, and bear on the tiji several denticles of
unequal size, as also along their inner edge a dense fringe of fine spinules.

The uropoda (ibid.) have the terminal plates of very unequal size, tlu' inner plate
scarcely projecting beyond the telson, w^hereas their exterior i>late is much larger and
somewhat oblong in form, having, as in the other species, a small ledge-like projection at
the outer edge, near the base. The auditory apparatus within the base of the inner
plate would seem to be quite rudimentary, indeed well-nigh obsolete.

The nervous cord (see fig. 12) exhibits a structure somewhat differing lium that
described by the author in Mi/sis relicta. The ganglia of the anterior division of the
body, exclusive of the brain or supra-oesophageal ganglion, are not, as in that Mysidan,
connate, but distinctly defined, though lying, as it were, imbedded in a common sheet of
connective tissue. On closer examination, eleven separate ganglia may be readily
counted, connected together by very short double commissures; but these commissures

182 THE VOYAGE OF H.M.S. CHALLENGER.

would not seem to be fibrous but rather of a similar cellular structure to that of the
wantrlia themselves. On the other hand, the ganglia of the tail are connected by very
lono- and narrow, distinctly fibrous commissures, placed close together.

The colour of the animal, in a fresh state, as observed on the Norwegian North
Atlantic Expedition, was a uniform pale red.

Habitat. — Several specimens of this magnificent Mysidan were collected on the
Challenger Expedition in the Southern Ocean from very great depths. The following is
a list of the Stations : —

Station 147, December 30, 1873 ; lat. 46° 16' S., long. 48° 27' E. (off Crozet Islands) :
depth, 1600 fothoms ; Diatom ooze; bottom temperature, 34°"2.

Station 157, March 3, 1874 ; lat. 53° 55' S., long. 108° 35' K; depth, 1950 fathoms;
Diatom ooze ; bottom temperature, 32° "l.

Station 158, March 7, 1874 ; lat. 50° 1' S., long. 123° 4' K; depth, 1800 fathoms;
Globigerina ooze ; bottom temperature, 33°"5.

Distribution. — The geographical distribution of this form is very remarkable, ranging,
as it does, within the limits of well nigh the same region in both hemispheres, and not
occurring in the intermediate tracts of the ocean. As it cannot be reasonably assumed
that the species has originated independently in both hemispheres, the physical condition
of the sea-bottom must at some time or other have been more uniform than at present,
to have admitted of the species spreading over a much more extensive area, whereas at a
later period essential changes in the climatological conditions must be assumed to have
caused this form to withdraw successively from the equatorial region towards the two
poles, thus dividing the species into two widely separated stocks, inhabiting correspond-
ing regions in both hemispheres. Another fact, too, viz., the remarkable occurrence, as
stated above, of the northern form, Lophogaster typicus, M. Sars, in the Southern Ocean,
without its being ever met with in the intermediate tracts, may also warrant the assump-
tion of essential changes in the physical conditions of the sea-bed having taken place at
some former period, thus causing the occui-rence of certain species to appear discontinuous.

44. Boreomysis obtusata, G. 0. Sars (PL XXXIII. figs. 1-6).

Boreomyds obttisata, G. O. S;iis, Preliminary Notices on the Challenger Schizopoda, No. 42.

Specijic CJmracters. — Male : — Anterior part of carapace not keeled above nor forming
anj" distinct rostral projection, the frontal margin being bx'oadly rounded, with but a very
slight angle in the middle ; antero-lateral lobes sharj)ly pointed. Eyes well developed,
rather short and broad, almost circular, cornea greatly expanded, with reddish pigment.
Antennular peduncle rather stout, with second joint very short, discoidal. Antenna!
scale oblong, tapering, upex narrowly truncate, denticle of outer corner but slightly
projecting. Propodal joint of legs subdivided into three distinctly defined articulations.

REPORT ON THE SCHIZOPODA. 183

Telson somewhat narrowed in outer part, apical incision occupying scarcely one-fifth of
the length of the telson, rounded at bottom ; terminal lobes narrow, obtuse at tip.
Length, 30 mm.

Memarks. — ^This species is nearly allied to the two northern species Boreomysis
nobilis, G. 0. Sars, and Boreomysis tricomis, G. 0. Sars, but may at once be distinguished
by the obtusely rounded frontal margin, that exhibits neither a distinct rostral projec-
tion, nor any trace of lateral processes.

Description. — Only two specimens — both adult males — are comprised in the collec-
tion, one of which is somewhat defective. The larger of the specimens measures 30 mm.
in length.

The foi'm of the body (see PI. XXXIII. fig. 1) is somewhat short, nearly as in the
Norwegian species Boreomysis tricomis, the tail only slightly exceeding in length the
anterior division of the body.

The carapace is rather large, covering, as in the preceding species, the whole of the
trunk, saving a very small part of the last segment that appears exposed above within
the bottom of the posterior emargination. The anterior part, in front of the cervical
sulcus, is evenly arched above, without any dorsal keel, and the frontal margin forms an
almost even curve, without any distinct rostral projection, presenting but a very slight
and inconspicuous angular prominence in the middle (see figs. 2, 3). The antero-lateral
lobes are rather produced and sharply pointed at the tip.

The caudal segments are cylindrical, and, as usual in the males, rather thick and
muscular, the last somewhat elongate, about as long as the two preceding taken together.

The eyes (see figs. 1, 2) are perfectly normal in structure, and rather short and thick,
almost circular, and somewhat flattened, with the cornea greatly expanded and provided
with a dark reddish pigment and well-developed visual elements.

The antennular peduncle (ibid.) is rather stout and somewhat similar to that in the
typical species, the second joint being extremely short, almost discoidal. At the
extremity of the peduncle, beneath the insertion of the flagella, is seen the male appendage,
which is very short, tuberculiform, but furnished with a dense tuft of delicate sensory hidrs.

The antennal scale (fig. 4) projects considerably beyond the antennular peduncle,
without, however, attaining double its length. It is oblong-linear in form, tapering
toward the apex, which is narrowly truncate, with the denticle of the outer corner but
slightly projecting.

The legs are rather slender, and have all the propodal joints subdivided into three
distinctly defined articulations (see fig. 5), the first of which is much the largest, and
provided at the inner edge with several bunches of slender setae. The exopods are, as
usual in the males, very powerfully developed, having the basal part broad and com-
pressed; they do not by any means, however, attain such a remarkable length as in the
preceding species.

184 THE VOYAGE OF H.M.S. CHALLENGEK.

The caudal limbs are developed precisely as in the males of the other species of the
geuus, constituting powerful natatory organs, with very elongate and multiarticulate
branches. In tlie first pair, however, the inner branch is, as usual, non-articulate,
forming an oblong membranous plate, with a short lateral expansion at the base.

The telson (fig. G) is a trifle longer than the last segment and somewhat slender, as
compared with that of the preceding species, Avith the outer part narrowed and densely
fringed with small, slightly unequal, denticles. The apical incision does not full}- occupy
one-fifth of the length of the telson, and is narrowly rounded at the bottom, as also
fi'inged with numerous short spinules. The terminal lobes are somewhat narrow and
obtusely rounded at the tip, and their apical denticles would not seem to exceed in
length the lateral.

The uropoda exhibit much the same appearance as in the two Norwegian species
Boreomysis arctica and Boreomysis tricornis, having both plates somewhat more slender
than in Boreomysis scyphops.

Habitat. — The two specimens contained in the collection were both taken in the
North Pacific in the following localities : —

Station 232, May 12, 1875; lat. 35° 11' N., long. 139° 28' E. (ofi" coast of Japan);
depth, 345 fathoms; green mud; bottom temperature, 41°"1.

Station 252, June 12, 1875 ; lat. 37° 52' N., long. 160° 17' W.; depth, 2740 fathoms ;
red clay ; bottom temperature, 35°'3.

45. Boreomysis microps, G. 0. Sars (PI. XXXIII. figs. 7-10).

Boreomysis microps, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 43.

Specific Chai'acters. — Female : — Form of body somewhat more slender than in the
preceding species. Frontal margin of carapace arched, with a small pointed projection
in the middle. Last caudal segment elongate, tapering. Eyes unusually narrow, almost
fusiform, with cornea not in the least expanded, and occupying but a small part of the
eye. Antennular peduncle relatively more slender than in Boreomysis ohtiisata.
Antennal scale surpassing antennular peduncle by only one-fourth of its length, oblong-
linear, apex obtusely truncate, with denticle of outer corner very small. Telson exceed-
ingly slender and greatly narrowed- in outer part ; lateral edges armed with strong
denticles along with numerous much smaller ones ; apical incision occupying only from
one-.seventh to one-eighth of the length of telson, very narrow at bottom ; terminal lobes
rounded at tip. Length, 24 mm.

Remarks. — The present form may be at once distinguished fntm the other species of
the genus by its unusually small and narrow eyes, a character from which the specific
denomination was taken. Moreover, the slender form of the telson would seem to afford
a good specific mark.

REPORT ON TJIE iSCJIlZuroDA. 185

Description. — Only one spefinicii, a Inokcii adult female, is comprised in the collec-
tion. It has a length of 24 mm., and is thus somewhat smaller than the last species.

The form of the body (see PI. XXXIII. fig. 7) would appear to be a trifle moic
slender than in the last species, and the tail is in particular relatively more elongate, as
compared with the anterior division.

The carapace is rather large, and (exhibits the usual form, with the cervical sulcus
very strongly marked, and' the posterior edge evenly emarginate in the middle, exposing
above a .small portion of the last segment of the trunk. The frontal margin (see fig. 8)
is evenly arched at the sides, and exhil)its in the middle a small pointed projection, the
rudiment of a rostrum.

The tail tapers somewhat backwards, and has the last segment very elongate,
exceeding in length the two preceding segments taken together.

The eyes (see fig. 8) are comparatively small, and exhibit a form somewhat differing
from that in the other species, being narrowly clavate, or almost fusiform, with the
cornea not in the least expanded, and occupying but a very small part of the eye. The
ocular pigment is, as in the last species, of a reddish colour.

The antenuular peduncle {ibid.) is somewhat more slender than in Boreomysis
obtusata, though in other respects exhibiting the usual structure.

The antennal scale [ibid.) is less produced than in the two preceding species,
projecting, as it does, beyond the antennular peduncle by only one-fourth of its length.
It has an oblong-linear form, with the greatest breadth about in the middle, and the
a|Dex obtusely rounded, with the denticle of the outer corner very small.

The legs would seem to agree in structure perfectly with those in Boreomysis
obtusata.

The telson (fig. 9) is exceedingly .slender and elongate, exceeding perceptibly in
length the last segment, and has the outer part much narrowed. The lateral edges are
in the greater part of their length armed with rather strong denticles, having between
them a great number of much smaller ones. The apical incision is comparatively short,
occupying only from one-seventh to one-eighth of the length of the telson, and rather
narrow, having, however, at the bottom a peculiar dilatation (see fig. 10). The edges of
the incision are, as usual, coarsely spinulose, and the terminal lobes rounded at the
tip.

Of the uropocUi the outer plates had been broken oS" in the specimen examined ; the
inner plates were very slender, lanceolate, and projected perceptibly beyond the tip of
the telson.

Habitat. — The sole specimen described above was taken in the North Atlantic south
of Nova Scotia, United States : —

Station 50, May 21, 1873; lat. 42° 8' N., long. 63° 39' W.; depth, 1250 fothonis ;
blue mud; bottom temperature, 38°"0.

(ZOOL. CHALL. EXP. — PART XXXVII. 188.5.) Oo 2-i

186 THE VOYAGE OF H.M.S. CHALLENGER.

Genus 3. AmhIyo2)s, G. 0. Sars, 1872.
Ambhjops, (!. O. Sars, Monograpbi over Norges Mysider, Bd. ii.

Genetic Characters. — Form of body comparatively thickset. Carapace large,
covering greater part of trunk, frontal margin evenly arched, without any trace of a
rostral projection. Eyes imperfectly developed, transformed into two immobile plates,
extending horizontally in front of the carapace and contiguous in the middle. Anten-
nular peduncle short and thick, with last joint largest ; male appendix well developed.
Antennal scale with outer edge naked, and jutting out at the end as a dentiform projec-
tion. Oral parts of usual structure. Gnathopoda having endopod comparatively poorly
developed. Legs subequal, of moderate length, propodal joint subdivided into three
articulations, terminal joint unguiform. Marsupial pouch composed of but two pairs of
distinctly developed incubatory lamellge. Sexual appendages in male short and thick,
with a transverse row of curved apical bristles. Caudal limbs in male natatory. Telson
linguiform, not incised at apex, outer part coarsely spinous at edges. Inner plate of
uropoda much shorter than outer.

Remarks. — Of this genus, which is closely allied to the genus Pseudomma, G. 0. Sars,
a single species only, AmhIyo2}S abbreviata, G. 0. Sars, from the Norwegian coast, has
hitherto been recorded. Another form, evidently belonging to the same genus, has,
however, been taken on the Challenger Expedition in the southern hemisphere, and will
be described below.

46. AmUyops crozetii, Willemoes-Suhm. MS. (PL XXXIII. figs. 11-16).

Amblyujps crozetii, G. 0. Sars, PreliTiiinary Notices on the Challenger Scliizopoda, No. 44.

Specific Characters. — Male : — Form of body somewhat more slender than in th(>
typical species. Carapace almost entirely covering trunk, antero-lateral corners obtusely
truncate. Last caudal segment somewhat longer than preceding. Ocular plates rather
large, quadrilateral, with a small upturned papillary projection anteriorly. Antennal
scale scarcely twice the length of antennular peduncle, somewhat rhomboidal, denticle of
outer corner placed well-nigh in tlie middle of the length of the scale, inner corner
projecting as a narrow linguiform lobe. Legs rather slender, terminal part very narrow,
with first joint longer than both the others taken together. Telson relatively short,
scarcely as long as last segment ; apex broadly truncate, and armed with numerous strong
spines. Inner plate of uropoda projecting considerably beyond tip of telson, and about
half as long as outer; auditory apparatus imperfectly developed. Length, 29 mm.

Remai'ks. — This form has been bi-iefly recorded by the late Dr. v. Willemoes-Suhm
in his manuscript notes, as a new species, under the above appelhition, and a drawing

REPORT ON THE SClilZUPODA. 187

furuished of the animal viewed from above. It may at once lie distinguished from the
typical species, Amhlyops ahhrevlata, G. 0. Sars, by the deviating form of the antennal
scale and the telson, as also by the remarkably slender legs.

Description. — Only a single specimen of this form, an adull male, was procured on
the Expedition. It has a length of 29 mm., and thus considerably exceeds in size the
typical species, which attains a length of only 18 mm.

The form of tlic body (see PI. XXXIII. figs. 11, 12) is comparatively rather robust,
though somewhat less so than in the typical species, with the anterior division 1)Ut
slightly more dilated than the posterior.

The carapace is rather large, covering most of the trunk, and leaving but a small part
of the last segment exposed above. The anterior part is marked ofi' by a well-defined
cervical sulcus, and somewhat arched above, with the frontal margin forming in the
middle a perfectly even curve. The anterodateral corners of the carapace are obtusely
truncate, and the inferior margins rather incurved in the middle.

The tail is cylindrical and anteriorly only a trifie narrower than the anterior part of
the carapace. The five anterior segments are nearly uniform in length, whereas the last
is rather elongate, almost as long as the two preceding taken together.

The ocular plates are comparatively large, occupying, as they do, tlie whole breadth
of the frontal margin, and are perfectly well defined from each other, though contiguous
along their inner edge. They exhibit an irregular quadrilateral form, with the inner side
shortest, and forming a right angle with the anterior, which has a short, somewhat
upturned, papillary projection in the middle. The edges of the plates are quite smooth,
and no trace of any pigment or visual elements could be detected in the specimen
examined ; though a similar diftuse pink pigment, as in the typical species, may have
existed in the specimen, when still fresh.

The antennular peduncle is sliort and thick, with the terminal joint as large as the
two others taken together. The male appendage is comparatively shorter than in the
typical species, but furnished with a dense bunch of delicate bristles. The flagella were
broken off at a short distance from their bases.

The antennal scale (fig. 13) exhibits an appearance somewhat different from that in
the typical species, and is also relatively somewhat shorter, attaining scarcely twice the
length of the antennular peduncle. It is somewhat rhomboidal in form, the apex being
very obliquely truncate, with the inner corner greatly projecting as a narrow linguiform
lobe fringed round with long setaj, whereas the outer corner juts out as a strong dentiform
projection, placed almost in the middle of the length of the scale. The basal part of the
flagellum is but half as long as the scale, with the middle joint longest ; the terminal
part was broken in the specimen examined.

The legs (figs. 14, 15) are ratlier more slender than in tlie typical species, and very
narrow, especially the posterior ones (fig. 15), though still e.xhildtiug the structure

188 THE VOYAGE OF H.M.S. CHALLENGER.

characteristic of tho genus, the terminal ]>iu-t being subdivided into three articulations,
the first by far the longest, and having besides a distinct, though rather small terminal
claw. The exopods are very strongly developed, with exceedingly broad and muscular
basal parts.

The caudal limbs are also very powerful, natatory, and agreeing in structure with
those in the male of Ambhjops ahhreviata.

The telson (fig. 16) is rather short, attaining scarcely the length of the preceding
segment, and differs conspicuously from that in the typical species by the apex being
abruptly and broadly truncate, and even slightly emarginate in the middle, not as in that •
species narrowly rounded. It tapers very slightly, and has the outer part fringed with
numerous small denticles, those springing from the apical edge, about fourteen, being
somewhat more elongate. Moreover, in the middle of the apical edge is seen a small
tubercle, from which issue two slender and diverging setae.

The uropoda exhibit the usual structure, and have the outer plate rather large,
almost twice the length of the inner. The latter is lanceolate, and projects considerably
beyond the tip of the telson. The auditory apparatus at the base of this plate would
seem to be quite rudimentary, whereas in the typical species it is well developed.

Habitat. — The above described specimen was taken in the Southern Ocean off the
Crozet Islands, at a rather considerable depth. The locality is as follows : —

Station 147.— December 30, 1873; lat. 46° 16' S., long. 48° 27' E. ; depth, 1600
fathoms ; Diatom ooze ; bottom temperature, 34° "2.

Genus 4. Pseudomma, G. 0. Sars, 1869.
Pscudomma, G. 0. Sars, Nye Dybvands — Crustaceer fra Lofoten ; Christiaiiia Vid. Selsk. Forhandl., 1869.

Generic Characters.- — Form of body slender, almost cylindrical throughout. Carapace
small, not covering by far the whole trunk, frontal margin evenly arched, without any
rostral projection. Eyes quite rudimentary, forming merely broad petaloid expansions
of the ocular segment, partly connate in the middle, and not exhibiting the slightest
trace of pigment or visual elements. Antennular peduncle very short ; male a^jpendage
large, conical. Autennal scale more or less obliquely truncate, with inner corner pro-
jecting, outer jutting forth as a strong dentiform process. Gnathopoda having endopod
powerfully developed, with terminal joint densely hirsute. Legs exceedingly slender
and fragile, filiform, increasing in length posteriorly ; propodal joint subdivided into
three articulations, terminal joint obtuse and densely hirsute, not unguiform. Sexual
appendages of male very narrow, with a single apical bristle. Caudal liuil)s in male all
natatory. Telson Unguiform, with apex entire, apical spines elongate. Inner plate of
uropoda shorter than outer, with auditory apparatus distinctly developed.

Reuiarks. — Of this genus, chieHy distinguished by the peculiar rudimentary condition

REPORT ON THE SCHIZOi'ODA. 189

of tlie eyes and the extremely slender filiform legs, three northern species have been
recorded, viz., Pseudomma roseton, G. 0. Sars, Pseudomma affine, fJ. 0. Sars, and
Pseiidomma truncatum. Smith. Two additional species, to be described below, were
met with on the Challenger Expiulitiou, both in the southern hemisphere. They are
readily distinguished from each other by the form of the ocular plates and the antennal
scale, as follows : —

Ocular plates with upper face jilane ami outer edge serrate. Antennal scale oblong,
with inner corner only slightly projecting; spine of outer corner far removed from
base, . . . . . . . . .P. sarsii, Suhni.

Ocular plates divided by a longitudinal ridge, outer edge smooth. Antennal scale
lanceolate, with inner corner greatly projecting ; spine of outer corner placed close
to base, . . . . . . . . .P. aujitrale, G. 0. Sars.

47. Pseudomma sarsii, Willemoes-Suhm, MS. (PL XXXIV. figs. 1-3).

Psewlomma sarsii, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 46.

Specific Characters.- — Form of body very slender. Carapace evenl}- emarginatc
behind, leaving the two posterior segments of trunk uncovered above. Last caudal
segment longer than preceding. Ocular plates occupying almost the whole breadth of
frontal margin, obtusely truncate anteriorly, outer edge partly serrate, upper face plane.
Antennal scale oblong, with denticle of outer corner not far distant from apex, inner
corner but slightly projecting and bluntly rounded. Telson about as long as last
segment, linguiform, apex broadly rounded and armed with ten strong spines, the six
innermost rather long ; lateral denticles very small. Uropoda of usual structure.
Length, 14 mm.

Remarks. — This form was recorded by the late Dr. v. ^Yillemoes-Suhm in his
manuscript notes, under the above given name, and a figure added of the animal as
viewed from above. It is closely allied to the typical species, P.^mudomma roseum, G. 0.
Sars, or perhaps still more to the Ai'ctic form, Pseudomma truncatum. Smith, but may
readily be distinguished from both by a somewhat deviating form of the antennal scale
and bv the armature of the telson.

Description. — The usual length of this form would seem to be aboiit 14 mm., or
somewhat less than that of Pseudomma roseum. There is, however, in the collection a
single very mutilated specimen from the Antarctic Ocean, which is rather larger in
size.

The form of the body (see PI. XXXIV. fig. 1) is very slender, and rather similar to
that of Pseudomma roseum, being nearly cylindrical throughout, with the anterior
division but slightly dilated.

The carapace is comparatively small and narrow, not nearly covering the whole

190 THE VOYAGE OF II.M.S. CHALLENGER.

riunk, two segments of wliicli are partly exposed behind the posterior emurginatiou.
The anterior third jiart of the carapace is marked off by a well-defined and rather deep
cervical sulcus, and terminated with an evenly-arched frontal margin. The antero-lateral
corners are but very slightly produced, and obtuse-angled.

The tail is about twice as long as the carapace, and very slender, cylindrical, tapering
scarcely at all posteriorly, with the last segment much longer than the others.

The ocular plates are comparatively broad, and quite plane, extending horizontally
in front of the carapace, and occupying nearly the whole breadth of the frontal margin.
They are obtusely truncate in front, and separated in the middle by a very small cleft.
The outer edge is slightly arcuate, and finely serrate along its anterior part, forming,
together with the anterior edge, an obtuse angle. As in the other species, no trace of
pigment or any visual elements can be detected ; but the optic nerve forms, within the
ocular plate, a ramification exactly similar to that described by the author in Pseudomnia
roseum.

The antennular peduncle exhibits the usual form, being very short and thick, with
the last joint longer than the two others taken together. The male appendage is some-
what shorter than the last joint of the peduncle, and provided with the usual dense
bunch of hairs.

The antennal scale (fig. 2) is about twice as long as the antennular peduncle, and of
au oblong form, about three times as long as broad. The apex is somewhat oblic^uely
truncate, though not nearly to such an extent as in the other known species, and the inner
corner therefore appears but slightly produced and bluntly rounded. The denticle of the
outer corner is rather strong, and placed much nearer to the apex of the scale than in any
of the other species.

The endopodal parts of the legs, as also the terminal parts of the antennular and
antennal flagella, were broken off in all the specimens preserved.

The telson (fig. 3) has about the length of the last caudal segment, and exhibits a
somewhat linguiform shape, being broadest at the biise and tapering regularly toward the
apex, w^hich is broadly rounded or almost truncate. The lateral edges are armed in their
outer part, on either side, with about eight very small denticles, and from the apical edge
issue ten much larger denticles, increasing in size inwards, and assuming the character of
strong spines ; moreover, a small tubercle occurs in the middle, as in the other species,
bearing two very delicate and diverging bristles. As regards form, the telson of the
present species bears most similarity to Pseudomma truncatum, Smith, but in that species
the number of the terminal spines is much less, viz., not over six. F.-ieudomma ciffine,
G. 0. Sars, on the other hand, has no less than twelve terminal spines, but in that form
the apical edge is not distinctly defined from the lateral ones.

The uropoda exhibit the usual form, and have the auditory apparatus within the base
of the inner plates distinctly developed.

REPORT ON THE SCIllZOPODA. 191

ITahitat. — Of this form, wliicli may he regnidcMl a representative species of the genus
in the soutlicrn hemisphere, several specimens were collected off the Kerguolen Islands,
at a depth of 120 fathoms. A single and much larger, though rather mutilated specimen,
apparently of the same species, was taken in the Antarctic Ocean from a rather con-
siderable depth. The locality is : —

Station 153, Fol)ruary 14, 1874; lat. G5° 42' S., long. 79' 49' E.; depth, 1675
fathoms ; blue mud.

48. Psexidomma australe, G. 0. Sars (PI. XXXIII. figs. 17, IS).

Amhlyops nudralit<, G. 0. Sars, Pridiminary Notices on the Challenger Schizopoda, Xo. 4-").

Specific Characters. — Ocular plates comparatively smaller than in tlie ])receding
species, not occupying the whole breadth of the frontal margin, outer edge smooth, and
forming, along with anterior, a projecting corner, from which a longitudinal keel runs
across the plate, dividing it into an upper and a lateral area, the latter somewhat hollowed.
Autennular peduncle short and robust. Antennal scale twice the length of the
antennular peduncle, rather narrow, lanceolate, setose on both edges, spine of outer
margin placed close to base of scale.

Remarks.— Oi this species only a fragment — the most anterior part of the Ijody — was
found ill the collection. This fragment shows, however, some very striking peculiarities,
fully warranting the establishment of a new species. I formerly referred it to the genus
Amhlyops, but now find it, on closer examination, more" properly referable to the
genus P.'ieudomma, the structure of the ocular plates being more in accordance with that
in the latter genus.

Description. — The fragment — comprising the anterior part of the carapace, together
with the ocular plates, the antennute and antennae — had evidently belonged to a full-
grown male specimen. The length of the animal may have probably been about 10 mm.

The carapace is rather broad anteriorly, with the frontal margin forming an even
curve, and the antero-lateral corners almost right-angled.

The ocular plates (see fig. 17) do not occupy the whole breadth of the frontal margin,
and exhibit, moreover, a form somewhat deviating from that in the preceding species.
They are, as in that species, truncate anteriorly, and [)artly separated in the middle b}- a
short and narrow sinus or cleft, but have the outer edge quite smooth, and forming,
along with the anterior edge, a somewhat projecting corner. From the latter a longi-
tudinal keel runs across the plate dividing it into an upper part, which is nearly
plane, and a lateral one, distinctly hollowed along the middle (see fig. 18). As in
the preceding species, no trace whatever of pigment or any visual elements can be
detected.

The antennular peduncle has much the same appearance as in the last species, being

n>2 THE VOYACiE OF H.M.S. CHALLENGER.

comparatively short ami thick, with the last joint liy far the largest. The male appendage
also exhibits a very similar aspect.

The aiitennal scale (see fig. 17), on the other hand, looks very dissimilar, resembling
rather that occurring in the species of the genus Mysidopsis. It is about twice as long
as the antennular peduncle, and exhibits a very narrow, lanceolate form, with both
margins apparently fringed with setse in their whole length. On closer examination,
however, a dentiform projection is seen issuing from the outer edge, at a very short
distance from the base, and the part of the edge behind this projection does not exhibit
any seta3. Thus, the scale is, in reality, formed upon the same type as that in the other
species of the present genus, but is truncate obliquely to such an extreme degree, that
the inner linguiform-produced corner occupies well nigh the whole length of the scale,
whereas the outer corner has withdrawn to very near the base. The basal part of the
ilagellum is somewhat more produced than in the preceding species, being not much
shorter than the scale, and has the last joint the longest. The terminal part of both
this flagellum and those of the antennulas had been broken off near their bases.

Habitat. — The above-described fragment I found in a bottle containing several larvte
of Decapoda and other Crustacea, taken off the entrance to Port Philip, Bass Strait.
The locality is given below, as follows : —

Station 161, April I, 1874 ; lat. 38° 22' S., long. 144° 36' E.; depth, 33 fathoms;
sand.

Genus 5. Anchialus, Kroyer, 1861.
Anchialm, Kroyer, Nat. Hist. Tidsskr., 2''''" R^kke, Bd. i.

GeneHc Characters. — Form of body somewhat different in the different species.
Carapace more or less developed, with frontal margin produced in the middle. First
caudal segment in female with small horizontally projecting epimera. Eyes normally
developed. Antennular peduncle with male apjjendage very small, tuberculiform ; outer
flagellum forming a lamellar expansion at base. Antennal scale remarkably small, shorter
than basal part of flagellum, apex obliquely truncate. Legs subequal, densely setiferous,
with terminal part subdivided into a more or less considerable number of short articula-
tions, terminal claw quite obsolete. Caudal limbs in female partly obsolete, in male well
developed, natatory. Telson large, incised at apex. Inner plate of uropoda scarcely
shorter than outer ; auditory apparatus distinctly developed.

Remarks. — This genus, first established by Kroyer, is chiefly characterised by the
rudimentary condition of the antennal scale, the presence in the female of a pair of small
but distinct epimera on the first caudal segment, and the peculiar reduction of some of
the caudal limbs in the female, finally by the form and large size of the telson. Besides
the three species described below, a fourth, Anchialus agilis, has been recorded by the

REPORT ON THE SCHIZOPODA.

193

author from the Mediterranean. The species of this genus would seem to lead a pelagic
existence, most of them being met with at the surface of tlic sea.
The following is a synopsis of the Challenger species : —

Carapace with
posterior edge

straislit.

emarginatc,
exposing

Frontal plate abruptlj- truncate,

A. lypiciis, Krdyer.

the two posterior segments of trunk. Frontal

plate triangular, acutely pointed at tip, . A. angustus, G. 0. Sars.

none of the segments of trunk. Frontal margin

only slightly projecting in the middle, . A. pusillue, G. 0. Sars.

49. Anchialus typicus, Kroyer (PI. XXXIV. figs. 4-24).

AiKihialuji fi/picug, Krtiyer, Et Bidrag til Kundskab om Krubsdyrfamilieu ilysida; ; Nat.

Hist. Tidsskr., 2^'" Eaekke, Bd. i. p. 53, Tab. ii. figs. 7, a-l.
Mysis moebii, Dolirn, Untersuchuugen ilber Bau und Entwickelung der Arthropoden, II. ;

Zeitschr. f. wiss. Zool., Bd. xxi., 1871, p. .359, Tab. xxvii., xxviii. figs. 11-22.
AneJiialus trunedtm, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 47.

Specific Characters. — Form of body short and thit-kset. Carapace large, covering
whole of trunk, posterior margin straight. Frontal plate abruptly truncate at tip. Last
caudal segment a trifle longer tliau preceding. Eyes thick, claviform, cornea slightlj-
expanded, with light yello-ndsh pigment. Anteuuular peduncle short and stout, with
middle joint cup-shaped. Antennal scale exceedingly minute, rhomboidal, denticle of
outer corner obsolete. Gnathopoda very strong, with carpal joint in male projecting at
the inner edge as a pointed process. Legs comparatively short, with terminal part very
small, and divided into four to five articulations ; first pair in male having terminal part
dilated in the middle and armed with peculiar slender spines. Caudal limbs in female
distinctly developed on first segment only, those of male, strong, with basal lobe of inner
branch very broad, lamellar ; outer branch of fourth pair but slightly produced. Telf^on
very large, oblong linear, apical incision occupying one-seventh of the length. Uropoda
with inner plate somewhat larger than outer, and having the auditory aj^paratus but
slightly developed ; outer plate with exterior edge armed with a row of small denticles.
Marginal setae of both plates very small. Length, 9 mm.

Remarks. — I recorded this form in my Preliminary Notices as a new species under
the name oi Anchialus tnincatus, but now believe it to be identical with the Anchialus
typicus of Kroyer. The figures given by that author do not, it is true, corresjjond
exactly with the form examined by m5-self ; but I think this may be merely accounted
for by the imperfect drawings given l)y Kroyer. His description would seem, for the
most part, to accord with the present species. I cannot but l)t'licv(' that tliL' I'nrni
recorded by Dohrn as Mysis ?)(oe6u belongs to this species. As regards the Mediterranean
.species, Anchialus agilis, G. 0. Sars, the similarity to the presi'ut form, both in the

(zool. chall. EXP. — p.\RT xxxvii. — 1885.) Go 25

194 THE VOYAGE OF H.M.S. CHALLENGER.

external appearance and the structural details, is very striking. But, as the frontal
plate exhibits in both a totally different form, and the eyes, moreover, in the present
form have a very light pigment, whereas it is dark in the Mediterranean form, I j^refer
nevertheless to regard both as distinct, though very closely allied species.

Description. — The length of the body of the adult female is about 9 mm., that of the
male somewhat less.

The form of the body (see PI. XXXIV. figs. 4-6) is remarkably short and thickset,
with the anterior division rather dilated, the posterior much more slender and cylindrical
in form.

The carapace is comparatively very large, covering, besides the whole of the trunk,
also the anterior part of the first caudal segment. Its posterior margin, contrary to what
generally occurs in the Mysidse, is quite straight, without exhibiting the slightest trace
of the usual emargination in the middle ; and the lateral parts or wings are very deep
posteriorly, with their edges forming a strong curve. Anteriorly the carapace tapers
somewhat, and exhibits here the usual cervical sulcus, which is, however, not particularly
deep. The frontal margin juts forth in the middle as a rather broad, horizontally extend-
ing plate, abruptly truncate at the tip (fig. 7), not, as in the Mediterranean species,
acutely pointed. The antero-lateral corners of the carapace are but slightly produced
and almost right angled.

The first caudal segment exhibits in the female (see figs. 4, 5), on either side, a narrow
plate, arching over the corresponding limbs, and apparently representing a kind of
epiniera. These plates are, however, wanting in the male (fig. 6). The other segments
are simple cylindrical, and the last of them somewhat longer than the rest.

The eyes are comparatively short and thick, claviform, with the cornea slightly
expanded, and occupying about the outer half of the eye. The ocular pigment in all the
Challenger specimens, as also in those examined by Kroyer, is very light yellowish,
whereas in the Mediterranean form it is of the usual dark hue.

The antennular peduncle (fig. 8) is rather thick and somewhat dilated toward the
end, with the second joint exhibiting a rather peculiar, as it were, cup-shaped form, being
apparently hollowed out anteriorly to receive the base of the terminal joint. The latter
is about as long as the basal, and exhibits in the male on the lower face a very short
knob-shaped lobe, clothed with a dense bunch of delicate hairs. Of the flagella, the
outer, as usual, is the longer, and exhibits at the base a short lamellar expansion bearing
a dense row of curved sensory bristles.

The basal part of the antennae (see fig. 9) is rather thick and massive, and armed
interiorly, at the base of the flagellum, with a strong denticulate spine. The scale, on
the other hand, is exceedingly small, so as scarcely to be visible when the animal is
viewed from above (fig. 5). It exhibits a somewhat rhomboidal form, the apex being
obliquely truncate, with the inner corner slightly projecting and rounded off", the outer

REPORT ON THE SCHIZOPODA. 195

forming an obtuse angle, without any distinct tooth. The proximal part of the flagellum
projects widely beyond the scale, and has the middle joint by far the largest, the last
very short.

The anterior lip (fig. 10) is chiefly distinguished by its projecting anteriorly as an
exceedingly long and sharply pointed spine, denticulate at the edges.

Tlie posterior lip (fig. 1 I) has its terminal lobes narrowly rounded in front, and finely
ciliate at the tip.

The mandibles (fig. 12) are developed in the usual manner, and have the armature of
their cutting edges (fig. 13) rather strong and somewhat difi'erent on the two mandibles.
The palp (see fig. 12) is rather large, with the middle joint lamellar, the last of oval
form and furnished with a double row of delicate bristles.

The first pair of maxillae (fig. 14) have the outer dentiferous lobe sharply incurved,
with a slight angular bend in the middle ; the inner lobe is rather small and quite mem-
branous, bearing at the edge several strong setae. The exognath is distinctly visible in
the form of a narrow lamellar expansion of the basal part, densely ciliate at the
edge.

The second pair of maxillae (fig. 15) exhibit quite a normal structure. The last joint
of the palp is comparatively small and of an oval form, with the outer edge naked. The
exognath is rather large, elliptical, and fringed with al:)out thirteen strong plumose .setae,
the posterior of which issues at some distance from the rest, and is more sharjily
curved.

The maxillipeds (fig. 16) are very strong, with the basal section clearly composed of
two very broad segments — the coxal and basal, — the former bearing exteriorly the
lanceolate epipodite, the latter exteriorly the exopodite, interiorly the strongly curved,
five-jointed endopodite, or palp. The terminal joint of the latter is very small and
armed witli a strong curved claw ; the four others are nearly uniform in size. No true
masticatory lobe can be detected at the inner corner of the basal section.

The gnathopoda (fig. 17) exhibit quite an unusually robust structure, especial)}' in
the male, and bear a much closer resemblance to the maxillipeds than to the true legs.
The basal part is very broad and muscular, and the carpal joint exhibits in the male a
strong triangular expansion of the inner edge, to wliich the terminal i)art admits of being
opposed.

The true legs (fig. 19) are comparatively short, and in the female uniform in
structure, with the terminal part remarkably small, not attaining by far the length of
the preceding (carpal) joint, and composed of only four articulations, the last of which is
quite rudimentary and almost hidden between tlu> bristles issuing from the preceding-
articulation ; in the posterior pair this part (fig. 20) is a trifle more elongate, and has one
articulation more than in the rest. In the male the first pair of legs (fig. 18) are
peculiarly modified, the terminal part being rather dilated in the middle, and bearing

19(3 THE VOYAGE OF H.M.S CHALLENGER.

from ten to twelve peculiar slender spines, forming together a dense fascicle. In all
the legs the basal part is rather fully developed and muscular, and the exopod very power-
ful, with broad and lamellar basal section and eleven-articulated terminal part.

The marsupial pouch in the female specimens (figs. 4, 5) was very large and pro-
truding, and filled with numerous ova or embryos. It is composed of three pairs of
incubatory lamellte, originating from the bases of the three posterior pairs of legs. Of
these lamellse, the anterior pair are rather small, whereas the posterior are exceedingly
large and curved.

The outer sexual appendages of the male (fig. 21) are slightly curved, and have at
the tip a transverse row of small sharply curved bristles.

Of the caudal limbs in the female, only the first pair (see fig. 22) are developed in
the usual manner, having the form of narrow stems, somewhat geniculate in the middle,
nnd supplied with a few short bristles. On the four succeeding segments the limbs are
represented by broad, immobile plates, contiguous in the middle, and closely appHed to
the ventral face, so as easily to be overlooked. These plates, which appear merely as
expansions of the sternal parts of the segments, have their edges somewhat angular, and
fringed with a few small bristles and short denticles.

In the male, all of the caudal limbs are modified to powerful natatory organs, with
broad and muscular basal parts and multiarticulate setiferous branches, the inner of which
exhibits at the base a remarkably broad and lamellar lateral expansion. In the first
pair (fig. 23) the terminal part of the inner branch is wholly wanting, but its lamellar
expansion still remains in its place. The fourth pair (fig. 24) are distinguished by the
outer branch being somewhat more produced than in the other paii's, and having the
outer articulations armed with short spines, instead of the usual natatory setse ; the
antepenultimate articulation of this branch is, moreover, produced on the outer side as an
acute-angled process (see fig. 25).

The telson (fig. 26) is very large, fully as long as the two preceding segments taken
together, and exhibits an elongate, almost linear form, its length being about three times
as great as its breadth. The lateral edges are almost quite straight and parallel, and
armed with a great number of small denticles, more crowded in the outer part. The
apex is cleft in the middle by a rather narrow incision, occupying about one-fifth of the
length of the telson, and the terminal lobes are obtusely pointed and provided at the tip
with a single denticle somewhat stronger than the lateral ones ; their inner edges are
throughout fringed with very fine spinules.

The uropoda (fig. 27) are highly distinguished by the very slight develoi^ment of the
marginal setse on the terminal plates, whereas both of the latter are partly spinous at
the edges. The inner plate is somewhat larger than the outer, and reaches the tip of the
telson ; it tapers regularly toward the apex, without exhibiting any conspicuous tume-
faction at the base, owing to the very slight development of the auditoiy apparatus ; its

KEPOKT ON THE SCHlZOPOpA. 10?

inner edge is coarsely spinous throughout, the spines being somewhat unequal in size, and
more especially the two apical ones rather large. The outer plate exhibits a form very
similar to that of the inner, but is somewhat shorter, and has the outer edge fringed with
a row of rather small, eijual-sized denticles, the posterior of which, however, issuing from
the ti}) of the plate, is somewhat stronger than the rest and slightly incurved.

As regards colour, the specimens preserved in spirit exhilnt a light brownish hue,
and have, moreover, a rather conspicuous dendritic pigmentary deposit on either side of
the carajjace behind the cervical sulcus.

Habitat. — Several specimens of this form, both males and females, were taken at the
surface of the sea off Cape of Good Hope. The locality is given as follows : —

Station ]41, December 17, 1873 ; lat. 34° 41' S., long. 18" 36' E.

The specimens examined by Kroyer were collected in the tropical part of the Atlantic,
in lat. 14° N.; those examined by Professor Dohrn were derived from the Museum at
Kiel, and stated to have been procured during the cruise of the Danish frigate "Galathea"
—the locality was not recorded.

50. Anchialus angustus, G. 0. Sars (PI. XXXV. figs. 1-18).

AnchialHs angustus, G. 0. Sars, Preliminary Notices on the Challenger SchizopoJa, No. 48.

Specific Characters. — Form of body slender and elongate. Carapace narrow, evenly
emarginate posteriorly and not covering the trunk comjjletely. Frontal margin jutting
out in the middle as an acute triangular projection, and forming on either side between
eye and base of antennae a similar triangular lobe ; antero-lateral corners rather broad
and projecting, acuminate at tip. Tail slightly tapering, anterior segment in female
with distinctly projecting cpimera, last segment rather elongate. Eyes narrow, well-nigh
cylindrical, cornea scarcely expanded. Antennular peduncle more slender than in preced-
ing species. Antennal scale of a similar appearance to the one in that species, but having
the denticle of the outer corner distinctlj^ developed. Gnathopoda less robust. Legs
having terminal part very slender and subdivided into seven articulations. The two poste-
rior pairs of caudal limbs in female imperfectly developed; outer branch of fourth pair in
male greatly produced, styliform. Telson very similar to that in Anchialus J ijpiciis,
but somewhat narrower. Inner plate of uropoda having auditory ajiparatus well
developed, outer jjlate about the same length, with only two spines, placed close together
in the middle of outer edge, terminal section linguiform. Marginal setae on both
plates well developed. Length, 10 mm.

Remarks. — This is a very distinct species, and at once distinguished from the pre-
ceding by its slender form and comparatively small and narrow carapace. It also exhibits
several differences in its anatomical details, though evidently belonging to the .same genus.

Description. — Of this form three specimens were found in the collection, two adult

198 THE VOYAGE OF H.M.S. CHALLENGER.

females (one of which has been mounted on a glass slide) and a broken male specimen,
which I thouglit it right to dissect for anatomical purposes. The length of the adult
female is 10 mm., that of the male about the same.

The form of the body (see PI. XXXV. figs. 1, 2) is much more slender and elongate than
in the typical species, and somewhat resembling that generally met with in the species
of Mysis ; the anterior division being very slightly dilated and about half as long
as the posterioi".

The integuments exhibit a peculiar, and, as it were, scjuamous sculpturing, most con-
spicuous on the ocular pedicles and the basal parts of the several limbs.

The carapace is comparatively small and narrow, contrary to what is found in the
typical species, not nearly covering the whole surface of the trunk, two segments of wliich
are exposed behind. It has, moreover, the posterior edge evenly emarginate in the
middle, and tapers anteriorly in such manner that its most anterior part does not exceed
in breadth the first caudal segment. The frontal margin juts out in the middle between
the eyes as an acute triangular projection, and forms, moreover, on either side, a similar
triangular lobe, projecting between each of the eyes and the base of the antennse. The
antero-lateral corners (see fig. 3) are rather broad and acuminate at the tip, and the
inferior margins of the carapace form at the side of the oral parts a very conspicuous sinus.

The tail is rather slender, cylindrical, though slightly tapering posteriorly. The first
segment exhibits in the female, as in the preceding species, on either side, a narrow
elliptical vaulted plate or epimeron, and the last segment is rather elongate, about as long
as the two preceding segments taken together.

The eyes are much narrower than in the preceding species, alnaost cylindrical, with
the cornea scarcely at all expanded, and not fully occupying the outer half of the eye.
The ocular pigment is of the usual dark hue.

The antennular peduncle (fig. 4) is less robust, with the second joint quite of a
normal form, the last regularly cylindrical, scarcely at all dilated at the end. The outer
flagellum has a similar lamellar expansion at its base to that of the typical species, and
the male appendage would also seem to be quite similar.

The antennal scale (see fig. 5) exhibits an appearance very nearly agreeing with that
in Anchialus typicvs, but is a trifle larger, having the denticle of the outer corner
distinctly developed, as also the marginal setse much coarser. A suture is seen to run
across the scale in close proximity to the inner corner, marking off" an obtusely triangular
terminal articulation, to which seven of the marginal setae are affixed. The proximal
part of the flagellum projects, as in the preceding species, considerably beyond the scale,
but has the terminal joint comparatively larger than in that form, and the basal spine
would seem to be somewhat smaller and quite smooth.

The oral parts, though developed upon the same type as in the preceding species,
still exhibit in their structural details well-marked specific differences.

REPORT ON THE SCHIZOPODA. 199

Thus, the spine issuing anteriorly from the anterior lip (fig. 6) is relatively much
shorter, and the terminal lobes of the posterior lip (fig. 7) are obtusely truncate in
front.

The mandibles (fig. 8) are chieily distinguished from those in the typical species by
the terminal joint of the palp being more elongate and narrow.

On the first pair of maxillte (fig. 9) the outer lobe is more regularly curv^ed, and the
rudimentary exognath somewhat shorter. On the second pair (fig. 10) the terminal joint
of the palp slightly difi"ers in foi-m, being comparatively shorter and broad in the middle,
and having, moreover, a dense fringe of delicate cilia along the outer edge.

The maxillipeds (fig. 11) are comparatively less robust, and have at the inner comer
of the basal part a distinct, densely setiferous masticatory lobe. The last joint of the
endopodite is triangular, and its apical spine shorter than in Anchialus typicus. The
epipodite, on the other hand, would seem to be comparatively larger.

The gnathopoda (fig. 12) are also much more slender than in the preceding species,
and agree more in structure with those in other Mysidans.

The legs (fig. 13) are densely setose, especially along their inner edge, the setae
exhibiting a conspicuous fascicular arrangement. The terminal part is rather produced
and very narrow, exceeding in length the preceding (carpal) joint, and is, moreover,
subdivided into a rather great number of short articulations, no less than seven being
counted on the middle pairs. The first pair of legs in the male do not seem in this form
to exhibit any difference from those in the female.

Of the caudal limbs in the female, the three anterior pairs are developed in the usual
manner, whereas the two posterior are represented merely by laminar expansions of the
sternal parts of the segments, as is in the preceding species the case with all saAdng the
first pair.

In the male, all the caudal limbs are natatory, but difier from those in the male of
Anchialus typicus by the basal expansion of the inner branch being far less developed
(see figs. 14, 15). Moreover, the outer branch of the fourth pair (fig. 16) is greatly pro-
duced, styliform, and composed of eleven articulations, the six outer of which are armed
with spines instead of natatory setae. Of the ' articulations of this branch the antepen-
ultimate is much produced, and bears at the end, exteriorly, a rather elongate spine ; the
two succeeding articulations, on the other hand, are very small, and the last of them
has two short apical spines.

The telson (fig. 17) exhibits an appearance very similar to that in the tjqjical species,
being, however, somewhat narrower and slightly tapering toward the apex, with twenty
to thirty lateral denticles on either side. The apical incision occupies about one-sixth of
the length of the telson, and has a form perfectly similar to that in Anchialus typicus.
The terminal lobes bear a rather elongate apical spine, and are densely fringed along
their inner edge with rather strong spinules.

200 THE VOYAGE OF H.M.S. CHALLENGEU.

Till' lu-dpoda (fig. 18) have both plates of ueaiiy equal length, ami, contrary to what
is the case in the typical species, are fringed with rather elongate plumose setaj. The
inner plate has, moreover, the inner edge, beneath the marginal setae, armed with
numerous unequal spines, some of which — disposed at regular intervals — are rather long.
The auditory apparatus within the base of this plate is much more fully developed than
in Anchialus typicus, the otolith being rather large and of a rounded oval form. The
outer plate is armed with only two spines issuing from a ledge-like projection at about
the middle of the exterior edge, and has the outer part liuguiform and setose all round.

Habitat. — The three above-mentioned specimens were all collected in the same
locality, at the entrance of Port Philip, South Australia. The locality is given below as
follows : —

Station IGl, April 1, 1874; lat. 38° 22' S.,long. 144" 36' E. ; depth, 33 fathoms; sand.

51. Anchiahis pusillus, G. 0. Sars (PI. XXXV. figs. 19, 20).

Promysis (?) pusilla, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 54.

Specific Characters. — Form of body rather short, with anterior division considerably
dilated, tail very narrow. Carapace completely covering the trunk, slightly emarginate
posteriorly ; frontal margin forming in the middle an obtuse angle, antero-lateral corners
obtusely rounded. Last caudal segment remarkably elongate. Eyes slightly expanded
at apex with dark jiigment. Antennular peduncle rather stout, outer Hagellum very
elongate. Antenna! scale less rudimentary than in the other species, denticle of outer
corner well defined. Legs slender, with terminal part short, triarticulate. Caudal
limbs in female very small, almost obsolete. Telson elongate, scarcely shorter than
uropods. Length, 3 mm.

Remarks. — I have recorded this form in my Preliminary Notices as a species of
the genus Promysis, Dana. On closer examination I have, however, found this to be
incorrect, and now believe that it should more properly be referred to the genus
Anchialus, exhibiting, as it does, several characters in common with the latter genus,
not to be met with in the former. My examination of the species has not been so close
as could lie wished, since both the specimens in the collection were mounted in Canada
balsam on a glass slide, and in such a position as not to admit of examining all the parts
satisfactorily.

DescripAion. — Both the specimens in the collection are females, with greatly developed
marsupial pouches, and thus may be assumed to have attained their full size. Not-
withstanding this, their length does not exceed 3 mm., and this form may accordingly
l)e^regarded as a true dwarf Mysidan.

The form of the body (see PI. XXXV. fig. 19) is comparatively short, with the
anterior division considerably dilated, whereas the tail is exceedingly narrow.

IIEPORT ON THE SCHIZOPODA. 201

The carapace is rather hirge, completely covering the trunk, uo segments of which
appear exposed. It is very slightly emarginatc posteriorly and has rather a deep cervdcal
sulcus, marking off its anterior part. The frontal margin is evenly arched at the sides,
and forms in the middle a slight angular projection. The antero-lateral corners are but
slightly produced and obtusely rounded.

Jlic caudal segments arc somewhat depressed and of uniform breadth, being much
narrower than the anterior part of the carapace. The last segment is remarkably
elongate, almost as long as tlie three preceding ones taken together.
• The eyes are claviform, with the cornea somewhat expanded, and exhibiting a dark
coloured pigment.

The anteunular peduncle is comparatively very powerfully developed, about half as
long as the carapace, and has the last joint distinctly the largest. Of the ilagella, the
outer one is remarkably elongate, almost equalling the whole body in length.

The antennal scale (see fig. 20) would seem to be constructed upon the same type as
in the two preceding species, being rather short as compared with that in most other
Mysidans, though not quite so rudimentary as in the other species of the genus, reaching,
as it does, to al)uut the middle of the antennular peduncle. The apex is somewhat
obliquely truncate, with the denticle of the outer corner well defined. The basal part of
the flagellum projects beyond the tip of the scale, as in the two preceding species, and
has the middle joint by far the largest.

The legs appear to be rather slender, Ijut have the terminal part comparatively short,
and composed of only three articulations.

The marsupial pouch was greatly developed in both specimens, forming a very large,
almost semigiobular prominence issuing from beneath the posterior part of the trunk.

The caudal limbs would seem to be exceedingly small, well nigh obsolete.

The telson is rather elongate and narrow, but its form could not be exactly made out
in the specimens examined.

The uropoda have both plates about equal, and fiiuged with long setaj. The auditory
apparatus within the base of the inner plate is distinctly developed.

Habitat. — The two specimens in the collection were taken in tlie Celebes Sea,
October 22, 1874; lat. b" 44' N., long. 123° 34' E.; at Station 199, most probably at
the surface of the sea.

Genus 6. Mysidopsia, G. 0. Sars, 1864.

Mysidopsis, G. O. Sars, ISeretning om en i Sommeren 1863 foretagen zoologisk Ec-ise, Nyt Magazin

f. NaturviJ., 1864.

Generic ^Characteys. — Carapace comparatively small, not completely covering the
trunk ; frontal margin more or less produced in the middle. E}-es well developed,

(ZOOL. CIIALL. EXP. PART XXXVII. — 1885.) Oo 26

•2&2 THE VOYAGE OF H.M.S. CHALLENGER.

pyrifonn. Anteniiular peduncle of usual form ; male appendage rather large. Antennal
scale lanceolate, setose on both edges, with a short apical articulation. Mandibles without
any distinct molar jirotuberance. First pair of maxillaj with inner lobe very small ;
second pair wanting the inner setiferons expansion of the basal part ; terminal joint
of jmlp oblong, not incurved ; exognath very narrow. Maxillipcds and gnathopoda
powerfully developed. Legs subequal, comparatively short and stout, with the joints
paitlv appressed, propodal joint subdivided into three articulations, terminal joint
having a slender, setiform claw. Marsupial pouch composed of three pairs of incubatory
lamoUse, anterior jjair very small. Male sexual appendages short and thick. Cauda!
limbs in male all natatory. Telson comparatively short, subtriangular, apex entire,
or cleft. Uropoda with inner plate much shorter than outer ; auditory ajiparatus well
developed.

Remarks. — This genus, established by the author as early as 1864, is chiefly
characterised by the form of the antennal scale, the structure of the mandibles and of
the maxillse, the comparatively robust form of the legs, finally by the form of the telson.
From the genus Mysis, to which it has some resemblance in its general aspect, it is easily
distinguished by the caudal limbs in the male being all natatory. To the genus Promyds
of Dana it would seem to be nearly allied, if not actually the same. But, as Dana says
that the terminal part (" tarsus ") of ilie legs in Promysis is not subdivided, whereas in
all species of the genus Mysidopsis it is distinctly triarticulate, I have not felt warranted
in identifying the two genera. Moreover, the species of the genus Promysis are pelagic,
whereas those of llysklojjsis are true bottom forms.

Three northern species, viz., Mysidopsis didelphys, Norman, Mysidopsis gibbosa, G. 0.
Sars, and Mysidopsis angusta, G. 0. Sars, have hitherto been recorded, and on the
ChaUeuger Expedition a fourth species, apparently belonging to the present genus, has
been procured and will be described below.

52. Mysidopsis incisa, G. 0. Sars (PL XXXV. figs. 21-23).

Mysidopsis (?) incisa, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 49.

Specific Characters. — Form of body rather slender. Carapace small, exposing the
two posterior segments of trunk, frontal maigin but slightly projecting in the middle.
Last caudal segment longer than preceding. Eyes large, cornea much expanded and
deeply emarginate above. Antennal scale narrowly lanceolate. Legs comparatively
feeble, with the joints only slightly expanded. Telson shorter than last segment, lateral
edges denticulate throughout, apex deeply cleft, incision occupying about one-fourth of
the length of the telson and bordered with delicate spinules ; terminal lobes pointed, with
apical spines not stronger than lateral denticles. Length, 8 mm.

Remarh. — T have felt warranted in referring this form to the genus Mysidopsis.

REPORT ON THE SOHIZOPODA. 203

since in most respects it would seem to agree pretty well with that genus. The telson,
it is true, has the apex not entire as in the typical species, Mysidopsis didelphijH; but
there is another species, undoubtedly belonging to this genus, viz., Mijsidopsis autjusta,
which likewise has the telson cleft at the tip, although the borders of the incision in that
species are smooth, and nf)t spinulose.

Description. — Of the present form only a single mutilated specimen, an adult female,
was found in the collection. It has a length of about 8 mm.

The form of the body (sec PI. XXXV. fig. 21) is comparatively slender, about as in
the northern form Mi/sidopsis angiista, but with the anterior division somewhat more
dilated.

The carapace, as in the other species of this genus, is rather small, not nearly covering
the whole of the trunk, the two posterior segments of wliich appear almost wholh-
exposed behind. Its anterior third is marked off by a well-defined cervical impression,
and is slightly arched above. The frontal margin forms only a very slight angular
projection in the middle, and the antero-lateral corners are olitusely rounded.

The caudal segments are all regular cylindrical, and the last of them somewhat longer
than the rest.

The eyes are comparatively large and slightly flattened, with the cornea much
expanded and deeply emarginate above. The ocular pigment is of the usual dark
hue.

The antennular peduncle does not attain any considerable length, and exhil)its the
usual structure. Both of the flagella were broken near their bases.

The antennal scale (fig. 22) projects only beyond the antennular peduncle by about
one-fourth of its length, and exhibits a narrow lanceolate form, with l)nih margins
setiferous throughout their whole length. The apical articulation is rather smdl, and
bears four of the marginal sette. The proximal part of the flagellum is much shorter
than the scale, and has the middle joint largest. The terminal part was broken in the
specimen examined.

Of the legs only one of the second pair remains in the specimen. Its structure would
seem to agree perfectly well with tliat in the other species, except that the joints ;ue
somewhat less expanded.

The two posterior pairs of incubatory lamellae composing the marsupial pouch are
seen in the fig. 21 ; the anterior rudimentary pair would seem to have been thrown ofl'
along with the corresponding legs.

The caudal limbs do not exhibit any peculiarities in their structure.

The telson (see fig. 23) is somewhat shorter than the last caudal segment, and
exhibits the usual triangular form, being broadest at the base and tapering rapidly toward
the apex, with the lateral edges almost straight, and armed on either side with close upon
sixteen small denticles, disposed throughout their whole lengtli. The apex is not, as in

204 THE VOYAGE OF H.M.S. CHALLENGER.

the typical species, entire, but deeply cleft in the middle, the incision being rather
narrow, and occupying about one-fourth of the length of the telson. The terminal
lobes are pointed and densely spinulose at their inner edge, and also furnished at the
tip with a few denticles of the same appearance as those occurring along the lateral
edfres.

The uropoda (see fig. 23) had the terminal part of both plates broken off in the
specimen examined, and their respective lengths cannot therefore be given. The
auditory apparatus within the base of the inner plate is well developed, with the otolith
rather laroe and slobidar.

Habitat. — The above described specimen was taken at the entrance of Port Philip,
South Australia, along with the specimens of Anchialus angustus. The locality is : —

Station 161, April 1, 1874; lat. 38° 22' S., long. 144° 36' E.; depth, 33 fathoms;
sand.

Genus 7. Siriella, Dana, 1852.

Siriella, Bana, United States Exploring Expedition, Crustacea, pt. i.
Cijiitliid, Thompson (male).

Generic Characters. — Form of body more or less slender. Carapace very small, not
nearly covering the whole of the trunk ; frontal margin produced in the middle. Eyes
normally developed. Antennular peduncle rather elongate ; male appendage but slightly
prominent, issuing from lower face of terminal joint. Antennal scale with outer edge
naked, and terminating in a small dentiform projection, apex obliquely truncate.
Mandibles with molar protuberance imperfectly developed. Second pair of maxillae
having but two masticatory lobes ; terminal joint of palp large and oblong, not incurved.
Legs subequal, rather stout, with propodal joint entire or subdivided into two articula-
tions only, and having a double row of densely crowded apical bristles ; terminal joint
forming a very strong falciform claw. Caudal limbs in male natatory, basal lobe of inner
branch usually transformed into two gill-like, more or less spirally twisted stems. Telson
elongate, densely spinose at the edges, apex entire, not incised. Outer plate of uropoda
broader than inner, and having an imperfect articulation at apex, outer edge partly
spinous. Auditory apparatus well developed.

Remarks. — The present genus is chiefly characterised by the structure of the legs,
which are more decidedly imguiculate than in any other known genus of Mysidans,
turther by the caudal limbs in the male having the basal expansion of the inner branch
converted into peculiar gill-like appendages, finally by the structure of the telson and the
outer plate of the uropoda. The genus is represented in most tracts of the ocean, and
comprises about ten different species, the greater part of which would seem to lead a true
pelagic existence, being met with at the surface of the sea, far from the coasts. The

REPORT ON THE SCHIZOPODA. 205

Challenger specimens belong to two diflferent species, to be described in the sequel. They

may easily be known by the following distinctive characters : —

Eyes ver}' large. Antennal scale linear. Telson exceedingly narrow, trnncate

at tip, ..... . . . . S. thornpsoni (M.-Edw.).

Eyes comparatively small. Antennal scale rhomboidal. Telsou linguiform, with

apex rounded, . . . . . . . . S. gracilis, Dana.

53. Siriella thompsoni (M. Edwards) (PI. XXXVI. figs. 1-24).

Cynthia sp., V. Thompson, Researches, p. 55, pi. vi.

Cynthia thomjjwni, ]\I. -Edwards, Histoirii nat. des Crustacfe, t. ii. p. 462, pi.

Siriella vitrea, Dana, Uiiitod States Exploring Expedition, Crustacea, jit. i. p. G56, pi. xliii.
figs. 6, a-m.
"i Siriella hrevipes, Dana, United States Exploring Expedition, Crustacea, pt. i. p. G60, pi. sliv.
figs. 3, a-h.

Cynthia inennis, Krtiyer, Nat. Hist. Tidsskr., 2'''=" Rrekke, Bd. i. p. 44, Tab. ii. figs. 6, a-g (male).
1 rromy»is yalathea;, Kroyer, Nat. Hist. Tidsskr., 2'>™ Ea-kke, Bd. i. p. 59, Tab. iL figs. 8, a-k (female).

Siriella edwardsii, Claus, Zeitschr. f. wiss. Zool., r>d. xviii. p. 271, pi. xviii.

Siriella thompsoni, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 50.

Specific Characters. — Foi-m of body not very slender. Frontal projection acutely
pointed. Last caudal segment shorter than the two preceding taken together. Ej^es
very large, with cornea greatly expanded. Antennal scale narrow, linear, apex somewhat
obliquely truncate. Propodal joint of legs undivided, terminal claw of moderate length.
Telson exceedingly narrow ; aj^ex truncate, with three small teeth between the innermost
pair of apical spines. Outer plate of uropoda much shorter than inner, with close upon
six spines on the outer edge. Length attaining 1 0 mm.

Remarks. — I cannot but assume, that all the forms described imder the different
names referred to above, belong to one and the same species, and tliat this is the one
first described by V. Thompson as Cynthia sp., and afterwards more fully designated b_v
Milne-Edwards as Cynthia thompsoni. As the generic name Cynthia has been long since
applied to a form of Ascidians, that proposed by Dana must of course be retained for
the genus. Originally, the name Cynthia was only applied to the males, and Siriella to
the females, the sexual diflfereuces being unknown till fully elucidated by Professor Claus.

Description. — The length of the lai'gest example collected is about 10 mm., but most
of the specimens in the collection are much inferior in size, though some of them are
apparently adult.

The form of the body (see PI. XXXVL figs. 1-3) is comparatively less slender than
in most of the other species, though not nearly so thickset, as represented in the figure
given by Dana of his Siriella vitrea, which form in my opinion is identical with the
present species.

The carapace is very small, not covering by fir the whole of the trunk, two segments
of which, and even a small part of a third, being exposed behind. It is evenly emarginate
posteriorly in the middle, and tapers a little anteriorly, hence not being broader in it.«!

206 THE VOYAGE OF H.M.S. CHALLENGER.

anterior part than is the first caudal segment. The cervical impression is well marked,
though not particularly deep. The frontal margin juts forth in the middle between the
eyes as a narrow triangular lappet, sharply pointed at the tip, but not very prominent.
The antoro-lateral corners of the carapace are obtuse-angled, and but slightly produced.

The caudal segments are simple cylindrical and taper very slightly posteriorly, the
anterior five about equal in length, whereas the last segment is somewhat more elongate.

The eyes are very large, pyriform, with the cornea considerably expanded, and
occupying the greater part of the eye. The ocular pigment is of a dark black colour.

The antennular peduncle is rather slender, almost half as long as the carapace,
and has the last joint in the female simple cylindrical, in the male (see fig. 4) slightly
dilated, and about as long as the basal. The male appendage is rather large, but only
slightly projecting in front of the peduncle, connate, as it is, with the lower face of the
terminal joint to its very base (see fig. 5). On removing the numerous fine hairs, with
which this appendage is clothed, the latter axe found to originate from a narrow band
doubled upon itself along the whole lower face of the appendage (fig. 5). Of the flagella,
the outer is much more elongate than the inner, and provided along its proximal part
with a row of delicate curved sensory bristles.

The antennal scale (fig. 6) does not quite reach the tip of the antennular peduncle,
■and exhibits a very narrow, linear form, about five times as long as l:)road. The outer
edge is perfectly straight and naked, terminating with a small dentiform projection.
The apex is somewhat obliquely truncate, with the inner corner slightly projecting. The
flagellum does not attain the length of the outer antennular flagellum, and has the
proximal part, or peduncle, shorter than the scale and very slender, with the middle joint
by far the largest, and the last exceedingly small.

The anterior lip (see fig. 7) is produced anteriorly as a spiniform projection, similar to
that occurring in the genus Anchialus.

The posterior lip does not exhibit any peculiarities in its structure.

The mandibles (see fig. 7) are of moderate size, with the armature of their cutting
edges (fig. 9) perfectly agreeing with that in the other species of the genus, and rather
differing from that in most other ]\Iysidans. Thus, the molar protuberance forms
merely a simple conical process, without any trace of the usual fluted surface. The palp
(see fig. 7) has the middle joint considerably expanded and laminar, whereas the last joint
(fig. 8) is comparatively narrow, with a dense row of ciliated bristles along the posterior
half of the inner edge.

The first pair of maxillaj (fig. 10) exhibit quite a normal structure.

The second pair of maxillae (fig. 11), on the other hand, are highly distinguished by
the absolute want of the posterior masticatory lobe, only two such lobes being found.
The palp is very fully developed, with the terminal joint rather large, oblong, and not
incurved. The exognath is comparatively small and elliptical in form.

REPORT ON THE SCllIZoruDA. 207

The in;ixilli2>eds (fig. 12) are more pediform than in most other Mysidans, tlie basal
sectiou being comparatively short, whereas the terminal part, or endopodite, is rather
l)roduced. The cpipodite is comparatively .small, and cxiiibits the nsnal lanceolate form
and membranovis structure.

The gnathopoda (fig. 13) are still more pediform, hut lathcr smaller than the true
legs, from which they moreover difler in the terminal j<iiut liting not unguiform but
lamellar, and. armed with numerous slender spines.

The true legs (figs. 14, 16) are comparatively less feeble in structure than in most
other Mysidans, and more decidedly ambulatory in their character, the propodal joint
being not multiarticulate and flexible, but C[uite rigid, and in the present species appa-
rently undivided, whereas in the other species a short proximal articulation may be
distinguished. From the tip of the propodal joint a double row of densely crowded and
very delicate, finely serrate bristles are seen to spring, forming a dense fascicle, between
which the terminal joint projects (see fig. 1 5). The latter has the form of a strong falciform
claw, resembling that in the higher forms of Macrurans. The posterior pair of legs (fig. 16)
are somewhat smaller and more slender than the rest, especially in the male, but do not
difler in structure. In all the legs, and likewise in the maxillipeds and gnathopoda, the
exopods are powerfully developed, with the basal part expanded and muscular, the
terminal i)art consisting of about ten short setiferous articulations.

The marsupial pouch in the female is, as in the other species of the genus, composed
of three pairs of incubatory lamellae, of which, however, the anterior pair are ver}" small.

The sexual appendages of the male (fig. 17) are comparatively small, and anteriorly
have three strong ciliate setae, the tip, moreover, being provided with a transverse row
of short curved bristles.

The caudal limbs in the female (fig. 2) exhibit the rudimentary structure character-
istic of the family. In the male (fig. 1), however, they are all strongly developed and
natatory, with a broad muscular part, and multiarticulate setiferous branches, being
moreover highly distinguished by the peculiar gill-like appendage originating at the base
of the inner branch. This appendage, which undoubtedly corresponds to the simple
lamellar expansion met with here in other male Mysidans, is divided into two cylindrical
stems of a quite gill-like sti'ucture, and iu the middle pairs (see figs, li), 21) these stems
are coiled up spirally, whereas in the first (figs. 18, 20) and la.st paii- they are well-nigh
straight. In the first pair, as usual, the terminal part of the inner branch is wholly
wanting, this branch being exclusively represented by the above-mentioned appendage
(see fig. 18). The fourth pau', which in male Mysidans generally exhibit some modifi-
cation of the outer brancli, would not seem to difler in any respect from the preceding pair.

The telson (fig. 22) is about as long as the two preceding segments taken together,
and remarkably narrow, being considerably constricted in front of the middle, with the
outer part almost linear and distinctly channelled along the dorsal face. The lateral

208

THE VOYAGE OF H.M.S. CHALLENGER.

edges are armed in their outer part with numerous small denticles, and have moreover,
near the base, on either side, three somewhat coarser denticles placed at some distance
from the rest. The apex (fig. 23) is abruptly truncate, and bears six rather strong spines,
the innermost jtair the largest, and, between the latter, three very small denticles occur,
besides two rather long and delicate setae (omitted in the figure).

The uropoda (fig. 24) are rather large, projecting considerably beyond the telson.
The inner plate is narrow lanceolate, with the auditory apparatus very fully developed,
and the inner edge, beneath the marginal sette, densely spinose. The outer plate is
appreciably shorter than the inner, Init rather broader, with the exterior edge armed, in
front of the terminal linguiform articulation, with about six spines, increasing in size
posteriorly.

As regards colour, the animal, according to Dana, is in a living state almost colourless,
though sometimes purply along the ventral face of the tail, and tinged with red at the
sides of the anterior division (the marsupial pouch). This purplish and reddish colour is
found to arise from stellate pigmentary deposits distrilmted with great regularity and
still retained in the specimens preserved in spirit. Thus, along the ventral face of the
tail is seen (figs. 1, 2, 3) on each segment a median and two lateral pigment-spots,
the one occurring at the end of the last segment being considerably ramified. On the
two posterior exposed segments of the trunk, similar pigment-spots may be seen, and
on either side of the marsupial pouch in the female (fig. 2), an exceedingly ramified
reddish pigmentary deposit may with facility be discerned. Moreover, at the inner side
of the antennular peduncle, similar pigmentary ramifications occur, extending to a
greater or less distance even into the inner fiagellum.

Habitat. — All the specimens in the collection were taken nt the surface of the sea.
The following is a list of the localities, with dates appended : —

Date.

Locality.

Between Tenerife and St. Thomas.

June 18 to 19, 1873.

North Atlantic.

October 5, 1873.

South Atlantic.

June 17, 1874.

Australian Seas, Sydney to Wellington.

April 3, 1875.

North Pacitic.

July 23, 1875.

North Pacific.

August to September 1875.

Pacific Ocean.

October IS, 1875.

South Pacific.

October 19, 1875.

South Pacific.

October 22, 1875.

South Pacific.

November 17, 1875.

South Pacific, off coast of Chili.

March 3 to 5, 1876.

South Atlantic.

March 14, 1876.

South Atlantic.

April 26, 1876.

North Atlantic, off Cape Verde.

April 29, 1876.

North Atlantic.

KEPOIIT ON THE SUlilZUPUDA. 209

The siiecimen exrimined by V. Thompson, and also those described bj- Milne-
Edwards and Kroyer, were from the Atlantic. Dana collected the species { = SirieUa
vitrea and Siriella hrevipes) in the Pacific. The specimens examined by Professor Glaus
were derived from the Museum in Hamburg ; locality not recorded.

Distrihution. — According to the localities stated above, the present species would
seem to have a very extensive geographical distribution, ranging, as it does, throughout
the North and South Atlantic, the Australian Seas, and the Pacific Ocean.

54. Siriella gracilis, Dana (PI. XXXVI. figs. 25-28).

SiricUa gracilis, Dana, United States l^xjiloring Expedition, Crustacea, i. p. 658, pi. xliv.

figs. 1, a-rj.
Siriella {/rarilig, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. .51.

Specific Characters. — Form of l)ody somewhat more slender than in Siriella
thompsoni. Frontal plate triangular, less acute. Last caudal segment as long as the two
preceding taken together. Eyes much smaller than in preceding species, cornea scarcely
expanded at all, and occupying but a small part of the eye. Antennal scale rhomboidal,
apex very obliquely truncate, inner corner projecting. Propodal joint of legs distinctly
subdivided into two articulations, terminal claw Yexy elongate. Telson linguiform, apex
evenly rounded, with a small tridentate plate issuing between the last pair- of elongate
spines. Uropoda with outer plate but slightly shorter than inner, and having a smaller
number of spines at the exterior edge. Length about 6 ram.

Remarks. — The jiresent species may be easily distinguished from the preceding by a
somewhat more slender form of body, the less developed eyes, and the deviating form of
the antennal scale and of the telson.

Description. — The length of the largest specimen in the collection does not exceed
6 mm., and this species is hence of rather smaller size than the preceding.

The form of the body (see PI. XXXVI. fig. 25) appears somewhat more slender than
in Siriella thompsoni, though not nearly to such a degree as in certain other species of
the genus.

The carapace exhibits a form very similar to that in Siriella thompsoni, but has the
frontal projection somewhat less pointed and triangular in form.

Of the caudal segments, the last is rather elongate, about as long as the two preceding
segments taken together.

The eyes are far from so fulh' developed as in Siriella thomjysoni, being but very
slightly expanded at the end, with the cornea occupying a comparatively small part of
the eye.

The antennular peduncle would seem to have the last joint relatively shorter than in
the preceding species, but for the rest it exhibits a very similar structure.

The antennal scale (fig. 26), on the other hand, is very different, being comparatively

(ZOOL. CHALL. EXP.^PAET XXXVII, — 1885.) Oo 27

I'lO THE VOYAGE OF H.M.S. CHALLENGER,

sliorter and broader, only three times as long as broad, and of a somewhat rhomboidal
form, the apex being very obliquely truncate, with the inner corner strongly projecting,
and the denticle of the outer farther removed from the apex than is the case in
Siric'lla thompsoni.

The leo's are somewhat more robust, and have the propodal joint distinctly
subdivided into two articulations, the proximal being the shorter. The terminal claw,
moreover, is comparatively much more elongate.

The telson (see fig. 27) is somewhat less slender than in the preceding species,
and has a decidedly liuguiform shape, the apex being evenly rounded, not truncate. The
lateral edges are coarsely denticulate along their outer part, and the posterior pair of
denticles, issuing from the apex, are considerably longer than the rest. Between the
latter projects (see fig. 28) a small tridentate plate bearing two delicate diverging
bristles.

The uropoda (see fig. 27) have the inner plate but very slightly longer than the outer,
and the auditory apparatus well developed. The outer plate has a smaller number of
spines at the exterior edge than in SirieUa thompsoni, not more than two or three being
frequently found.

The arrangement of the pigmentary spots on the body is very similar to that in the
preceding species. But in this form occurs in addition a richly arborescent pigmentary
deposit on the basal part of the telson, as also on the ocular pedicles.

Habitat. — Of this species, too, all the specimens in the collection were taken at the
surface of the sea, but somewhat sparingly, not more than one or two specimens being
taken as a rule in each place. The following is a list of the localities, with dates
appended : —

Date.

Locality.

September 13, 1874.

February 5, 1875.

February 1875.

April 3, 1875.

August 24, 1875.

August to September 1875.

Arafura Sea.

Ofi' Samboangan, Mindanao, Philippine Islands.

North of New Guinea.

North Pacific.

Tropical Pacific.

The specimens examined by Dana were collected in the Pacific at three difi"erent
localities.

Distribution. — To judge from the above stated localities, the distribution of the
present species would seem to be more restricted than is that of the preceding
form, it being exclusively met with in the Pacific Ocean and the seas of the Indian
Archipelago.

REPORT ON THE SCHIZOPODA. 211

Genus 8. Euchcetomera, G. 0. Sars, 1883.

Huchcetomera, G. O. Sars, Preliminary Notices on the Challenger Schizopoda.

Generic CJiaractei's. — Carapace not fully covering trunk, emarginate posteriorly ;
frontal margin slightly projecting in the middle. Eyes somewhat irregular in form,
cornea contracted in the middle. Antennular peduncle of moderate size ; male
appendage normally developed. Antennal scale with outer edge naked and terminating
in a dentiform projection, apex obliquely truncate, with inner corner projecting. Legs
very slender, increasing in length posteriorly, and provided with unusually strong
plumose setae, propodal joint subdivided into three distinctly defined and mobile
articulations, terminal joint unguifovm, esopods with terminal part very elongate and
flexible. Caudal limbs in female simple but rather large, laterally extended and fringed
with remarkably strong setae ; those of male all natatory. Telson remarkably short,
lamelliform, rounded, apex entire and provided with two long ciliated setae. Uropoda
with elongate and narrow plates, fringed all round with long setae, inner plate much
shorter than outer, and with auditory apparatus well developed.

Memarls. — The present new genus is cliicHy characterised by the unusually short,
lamelliform telson, agreeing somewhat in form with that of the genus Enjthrops,
G. 0. Sars ; also by the slender legs and the very strong development of the setae on the
several limbs. The species of this genus would seem to lead a pelagic existence as is the
case with those of the preceding genus, met with, as they are, at the surface of the sea
far from the coasts. Two species are represented in the collection, easily distinguished
by the armature of the telson, as follows : —

f with lateral edges denticulate, . . . . . . E. tijpica, G. O. Sars.

Telson

( without lateral denticles, . . . . . . . E. tenuis, G. O. Sars.

55. Euchcetomera typica, G. 0. Sars (PI. XXXVII. figs. 1-20).

Euchcetomera tijpico, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 52.

Specific Characters. — Form of body rather robust. Carapace broadly emarginate
posteriorly, exposing almost wholly the two last segments of the trunk ; frontal projection
acutely pointed. Last caudal segment comparatively short. Eyes of moderate size,
pyriform, projecting on either side, and separated at the base by a distinct interval.
Antennal scale oblong, somewhat curved, about four times as long as broad, spine of outer
corner remarkably strong. Telson fully as broad as long, with five strong lateral denticles
on either side. Length, 14 mm.

Remarks. — The examination of this and the following form, as regards external
appearance, has been somewhat diflicult, from the specimens being mounted on glass

212 THE VOYAGE OF H.M.S. CHALLENGER.

slides in shallow cells, whereby the body has been partially crushed and deformed. The
anatomical details have, however, been satisfactorily made out from the dissection of one
of the specimens.

Description. — The length of the adult female is about 14 mm., that of the male
nearly the same.

The form of the body (see PI. XXXVII. fig. 1) would appear to be rather short and
robust, with the tail relatively less elongate than usual, in proportion to the anterior
division.

The carapace does not nearly cover the whole of the trunk, the two posterior
segments of which are well nigh entirely exposed. It is evenly emarginate posteriorly,
and exhibits in its anterior part a distinct, though not particularly deep, cervical
impression. The frontal margin juts out in the middle as a narrow acuminate lappet,
projecting between the bases of the eyes and reaching to about the middle of the basal
joiut of the antennulse.

The tail does not exceed in length the anterior division of the body, and has the
segments rather thick in proportion to their length. The last segment only slightly
exceeds the preceding in length.

The eyes — separated at the base by a distinct interval — are of moderate size, and
extend to each side so as to project considerably laterally. They are pyriform in shape,
about as long as broad, wdth the cornea rather expanded, and exhibiting in the middle a
similar constriction to that seen in the species of the Euphausiidan genera, Thysanoessa,
Nematoscelis, and Sti/locheiron.

The antennular peduncle (fig. 2) presents quite a normal appearance, being somewhat
dilated towards the apex, with the last joint about as long as the basal, and having three
strong ciliated setae springing from the inner edge. In the male, a hairy lobe projects,
as usual, from the end of the peduncle beneath the insertion of the flagella. The latter
were both broken off near their base in the specimens examined.

The antennal scale (fig. 3) only slightly exceeds in length the antennular peduncle,
and exhibits an oblong-linear form, about four times as long as broad. It is somewhat
curved outwards, and has the exterior edge naked and slightly concave, jutting out at the
end as a very strong dentiform projection. The apex is obliquely truncate, having the
inner corner projecting and fringed, together with the whole inner edge, with about
seventeen unusually strong and densely cdiate setae. The proximal part of the flagellum
does not attain the length of the scales, and has the middle joint longest, with three
plumose setae at the end interiorly.

The anterior lip (fig. 4) exhibits the usual somewhat galeate form, with an obtusely
rounded prominence anteriorly.

The posterior lip (fig. 5) has the terminal lobes obliquely rounded and densely ciliatc,
with a slight angle exteriorlv.

REPORT ON THE SCHIZOPODA. 213

The mandibles (fig. 6) are powerfully developed, with the masticatory part consider-
ably expanded, and the cutting edges (fig. 7) exhibiting an armature similar to that
observed in most other Mysidans. The palp (see fig. 6) is longer than the mandible
itself, and has the middle joint largest, with a row of strong plumose setse along its outer
edge. Its terminal joint is lamelliform, and, besides a number of elongate setae, furnished
near the tip with a row of small spinules.

The first pair of maxillse (fig. 8) exhibit quite a normal appearance.

The second pair of maxillae (fig. 9) have the terminal joint of the palp rather large
and sharply incurved, oval in form, and furnished along the outer edge with seven
exceedingly elongate setae, the outer part of which is somewhat curved and quite naked,
whereas their proximal part is coarsely ciliate. The exognath is comparatively small and
triangular in form, with about nine marginal setae.

The maxillipeds (fig. 10) are rather strong, with the basal part jutting out at the end
interiorly as a small linguiform masticatory lobe. The joints of the endopodite are
comparatively broad and appressed, the last triangular, with a strong apical spine. The
exopodite is much longer than the endopodite, but very slender, ■with the basal part
rather narrow and the terminal part composed of ten articulations. The epipodite,
finally, is unusually small and oval in form, with four bristles springing from its upper face.

The gnathopoda (fig. 11) are, as usual, more pediform in character, though diflVriug
considerably in appearance from the true legs. The endopod is rather elongate, •with the
carpal and propodal joints largest and nearly equal in length, as also very movably
jointed together. The terminal joint is very small and densely hirsute ; it is sharply
incurved and exceedingly mobile, admitting of being bent in against the preceding joint.

The legs (fig. 12) are very slender and elongate, increasing somewhat in length
posteriorly, and are furnished, too, with unusually strong plumose setas. The terminal
part is somewhat longer than the preceding (carpal) joint, and subdivided into three
distinctly defined and mobile articulations, besides the apical claw (fig. 13), which is
well developed, though not particularly strong. Of the propodal articulations, the first is
by far the largest, in the anterior pair (fig. 1 2) about as long as the other two taken
together, in the posterior pair (fig. 14) still longer and much narrower.

The marsupial pouch in the female would seem to agree in structure with that of
Jli/sis.

The caudal limbs in the female (figs. 15, 16) constitute, as usual, simple, nou- articulate
narrow plates, but are somewhat larger and more projected laterally than in most other
Mysidans. Lloreover, their marginal setae are remarkably strong, and exhibit a ver}-
peculiar ciliation, the cilia being disposed in dense verticils at regular intervals (see
fio-. 17). In the male all the limbs are natatory, with multiarticulate setiferous branches.
In the first pair (fig. 18) the inner branch is, as usual, rudimentary and non -articulate,
and would seem to lack the basal expansion.

214 THE VOYAGE OF H.M.S. CH^LLENGEK.

The telson (fig. 20) exhibits an aspect most characteristic of the genus and quite
different from that usually met with in the Mysidse, save in the genus Erythrops, G. 0.
Sars. It is very short, lamelliform, fully as broad at the base as it is long, having the.
lateral edges armed on either side with five strong denticles, and the apex narrowly
truncate, bearing in the middle two very long and densely ciliate setse.

The uropoda (fig. 19) have the terminal plates very slender and fringed all round
with strong plumose setfB. The inner plate is much the shorter and lanceolate in form,
with the base considerably dilated and containing a fully developed auditory apparatus,
the otolith being rather large and of globular form. The outer plate is about one-fifth
longer than the inner, and very narrow, linear, though somewhat curved outwards and
truncate at the tip.

As to colour, the specimens preserved in glycerine were of a uniform light brownish
hue, without any trace of the stellate pigmentary spots found in the species of the
preceding genus.

Habitat. — Of this form onl}' three specimens were found in the collection, taken at
the surface of the sea in the North Pacific. The following is a list of the localities, with
dates appended : —

Date.

Locality.

June 28, 1875.
July 2, 1875.
July 12, 1875.

Station 244; lat. 35° 22' N., long. 1G9° 53' E.
Station 246; lat. 36° 10' N., long. 178° 0' E.
Station 252; lat. 37° 52' N"., long. 160° 17' W.

Quite recently I have had an opportunity, through the kindness of Mr. Hoyle, of
examining another specimen, a young female, of apparently the same species, taken
April 9, 1876, in the Atlantic. The specimen was mounted on a glass slide together with
a small Cephalopod and several other surface animals.

56. Eucluetomera tenuis, G. 0. Sars (PI. XXXVII. figs. 21-24).

Eachadomcra tenuis, G. 0. Savs, Preliminary Notices on the Challenger Schizopoda, No. 53.

Specific CJiaracters. — Form of body more slender than in preceding species, tail
especially much narrower, with last segment greatly elongate. Carapace comparatively
large, posterior emargination rather narrow, rostral projection very slight. Eyes greatly
expanded, broader than long, and close together. Antennal scale very narrow^ six times
as long as broad, denticle of outer corner small. Legs exceedingly slender, wdth scattered
but rather long bristles. Telson having lateral edges perfectly smooth, apex wath a
slight dentiform projection on either side. Length, 8 mm.

REPORT ON THE SCHIZOPODA. 215

Remarks. — The present species may be easily known from the preceding by its
exceedinoly narrow tail, the last segment of which is greatly elongate, by the short
and thick eyes, the narrow antennal scale, and the want of lateral denticles on the
telson.

Description. — Only a single specimen, apparently a young female, was procured during
the Expedition. It lias a length of 8 mm.

The form of the body (see PL XXXVII. fig. 21), somewhat deformed in the .specimen
by pressure, would appear to be much more slender than in ExichcEtomera typica, and
the tail in particular is remarkably narrow, as compared with the anterior division.

The carapace w^ould seem to be relatively larger than in the i)receding species, its
wings partly advancing over the first caudal segment. It exhibits, however, posteriorly
in the middle, a deep but narrow emargination, exposing the dorsal part of the two
posterior segments of the trunk. The frontal margin presents in the middle a very .slight
projection, scarcely reaching beyond the ocular segment.

The caudal segments are cylindrical, and the four anterior very short and subequal, the
fifth a trifle longer, and the last exceedingly elongate, nearly as long as the preceding
three taken together.

The eyes are greatly expanded toward the apex, being broader than long, and
originate close together, so as not to ^^rojcct laterally. The cornea exhibits, somewhat
anterior to the middle, a transverse constriction similar to that in the preceding species.

The anteunular peduncle appears somewhat more slender than in Euchcetomera tijpica,
but otherwise exhibits a very similar structure.

The antennal scale (fig. 22) is very narrow, linear, about six times as long as broad,,
and very slightly curved. As in the preceding species, the apex is obliquely truncate,
with the inner corner somewhat projecting and the outer armed with a dentiform pro-
jection, but the latter is far from so strong as in that species.

The legs (fig. 23) are extremely slender, and the posterior pair reach, when reflexed,
even beyond the last caudal segment (see fig. 21). In their structure they agi'ee "ndth
those in the preceding species, saving that the marginal setae are fewer in number and
also rather more elongate.

The telson (fig. 24) exhibits a short lamelliform shape similar to that of Euchceto-
mera tyjjica, being but very little longer than broad, but difi'ers materially in the lateral
edges being perfectly smooth, without a trace of the strong denticles occurring in that
species. The apex is narrowly truncate, with a very small dentiform projection on either
side, and the terminal setae placed close together.

The uropoda do not seem to diff'er essentially from those in Evchcetomera tijpica,
saving that their terminal plates are a trifle more slender.

Habitat. — The above described specimen was taken November 18, 1875, at the
surface of the sea, in the South Pacific, oft" the coast of Chili.

216 THE VOYAGE OF H.M.S. CHALLENGER.

Gcuus 9. Ilc'teromysis, Smith, 1874.

Heteromysis, Smith, Report upon the Invertebrate Animals of Vineyard Sound and adjacent waters.
Chiromysh, G. O. Sars, Middelhavets Mysider.

Generic Cliavacters. — Form of body comparatively short. Carapace emarginate
posteriorly, not covering completely the trunk, frontal margin projecting in the middle.
Eyes small. Antennal scale very minute, lamelliform, setose on both edges. First pair
of true legs much stronger than the rest, with propodal joint entire and spinous at inner
edo-e ; terminal joint unguiform. Remaining legs feeble in structure, with terminal part
multiarticulate and sctous, terminal claw obsolete. Caudal limbs in both sexes of same
structure, forming small, simple, non-articulate, setose plates. Telson comparatively
short, deeply cleft at apex. Inner plate of uropoda shorter than outer.

Remarks. — This genus, first established Ijy Professor Smith, is most prominently
characterised by the peculiar and strong development of the first pair of true legs, as
also by the caudal limbs in the male being of the same rudimentary appearance as in the
female. Three species of this genus have hitherto been recorded, viz., Hetcromysis
formosa, Smith, from the eastern coast of North America, Heteromysis microps, G. 0.
Sars, from the Mediterranean, and Heteromysis norvegica, G. 0. Sars, from the Norwegian
coast. A fourtli species, to he described below, was also taken on the Challenger
Expedition. All the species are decidedly littoral in character, being never met with
either in the open sea, or at any considerable depth.

57. Heteromysis bermudensis, n. sp. (PI. XXXVIII. figs. 1-7).

Specific Characters. — Form of body exceedingly short and thickset. Carapace
evenly arched above, frontal projection triangular. Last caudal segment not longer than
preceding. Eyes ovoid, cornea occupying about a third part of the eye, ocular pigment
dark. Antennal scale oblong-oval, about three times as long as broad. Telson triangular,
lateral edges armed on either side in their outer part with about six denticles ; apical
incision occupying third part of length of telson, somewhat broad, only inner half
bordered with spinules ; terminal lobes narrow, with two unequal apical spines. Length,
6 mm.

Remarks. — This species would seem to be most nearly related to the Norwegian
form, Heteromysis norvegica, G. 0. Sars, from which, however, it may be readily
distinguished by its much inferior size and more thickset form. It also exhibits great
resemblance to Heteromijsis formosa, Smith, but differs in the small size of the antennal
scale and the somewhat deviating form and armature of the telson. From the Mediter-
ranean form, Heteromysis microps, G. 0. Sars, it is likewise distinguished by the form
and armature of the telson, as also by its more fully developed eyes.

REPORT ON THE SCIIIZOPODA. 217

Description. — Only a solitaiy, somewhat mutilated specimen, an adult female, was
procured on the Expedition. It measures only 6 mm. in length.

The form of the body (see PL XXXVIII. figs. 1, 2) is remarkaljly short and thick-
set, more so than in any of the previously known species, with the anterior division
somewhat dilated.

The carapace is evenly arched above and deeply emarginate posteriorly, exposing the
dorsal part of the two last segments of the trunk. It has a distinct, though not \Qvy
sharply marked cervical sulcus, and its inferior margins are evenly incurved in the
middle. The frontal margin projects in the middle almost at a right angle, covering a
part of the ocular pedicles, and the antero-lateral corners are but slightly produced as
rather broad, obtuse-angled lobes.

The caudal segments are all well-nigh of equal length and a little depressed, their
breadth being somewhat greater than their height.

The eyes are comparatively small, of a regular ovoid form, and projecting but .sHghtly
at the sides. The cornea occupies about one-third of the eye, and has a dark pigment.

The antennular peduncle (fig. 3) is rather short and thick, with the last joint as large
as the basal, and the middle joint very obliquely truncate at the end.

The antennal scale (fig. 4) is exceedingly small, scarcely as long as the antennular
peduncle, and of an oblong-oval form, about three times as long as broad. It is fringed
all round with long setae (omitted in the figure), and has a very short terminal articulation.

The oral parts could not, of course, be examined closely in the sole specimen before us.

All the legs were broken oif, their basal parts only being left.

The marsupial pouch (see fig. 1) was fully developed in the specimen, and contained
young, in the so-called pupa stage (figs. 6, 7), agi-eeing perfectly with those of other
Mysidans.

Tlio tolson (fig. 5) is of a somewhat triangular form, broadest at the base, and
regularly tapering toward the apex. The lateral borders are in greater part quite smooth,
armed in their hinder part only, on either side, with about six denticles. The apical
incision is very deep, occupying, as it does, fully one-third of the length of the telson,
and also rather broad. The edges limiting the incision are quite smooth in their hinder
half, whereas a dense fringe of spinules runs along the anterior part, much as in the
Norwegian species. The terminal lobes are rather narrow, and bear on the tip two
somewhat unequal spines, the outer being the longer.

The uropoda (see fig. 2) do not exhibit any essential difi'erence from those in the
other species, their terminal plates being comparatively broad, and the inner plate much
shorter than the outer, with the auditory apparatus distinctly developed.

Habitat. — The above-described specimen I took from a small bottle containing
specimens of Paranebalia longipes (Willcmoes-Suhm), collected in shallow water at the
Bermuda Islands.

(ZOOL. CHALL. EXP. PART XXXVII. — 1885.) Oo 28

APPENDIX.

NOTES ON SOME PAEASITES OBTAINED FROM THE CHALLENGER SPECIMENS
OF SCHIZOPODA (Pl. XXXVIII. Figs. 8-23).

In the following pages I purpose directing the attention of zoologists to certain ecto-
and endo-parasites found infesting a few of the Challenger Schizopoda I have examined.
My intention is not to give full descriptions of these parasites, belonging, as they do, to
groups on which I have not been called upon to report. Meanwhile, I have not seen fit
to pass them by altogether, seeming, as they do, to exhibit quite a particular interest,
and, moreover, since they undoubtedly may serve to complete our knowledge of the
biology of the Schizopoda.

Long ago Kroyer recorded ' a peculiar Bopyridan infesting the Arctic Mysidan,
My sis oculata, Fabr., under the name of Dajus mysidis, which form has more recently
been described by Buchholtz ^ and Hoek' under a new generic name, viz., Leptoiihryxiis,
the latter authors having apparently not been aware of the figures and name given by
Kroyer in the above cited work. This form was the only known parasite found on
Schizopods, until the author recorded* three other Bopyridans, likewise met with on
certain Schizopods {Eurythrops, Amhlyops, and Pseudomma). These three Bopyridans
were found to belong to two distinct genera, viz., Aspndophryxiis, G. 0. Sars, and Noto-
phryxus, G. 0. Sars. Moreover, the author has observed, on species of the Mysidan
genus Erythrops, a peculiar Lernseid, apparently the Sphceronella leuchartii of Salenskj'.
All these forms are, however, true ecto-parasites. No endo-parasites, on the other hand,
have as yet been found in any form of Schizopods. But in a few specimens of
Euphausiidans from the Challenger Expedition, I have also succeeded in detecting two
forms of true endo-parasites, or intestinal worms, one of which, at least, exhibits a most
peculiar appearance and certain highly remarkable features. On PI. XXXVIII. I have
given fio-ures of all the parasites met with, for the most part in their natural position on
the Schizopods infested by them.

' Giiimard's Voya<^e en Scandinavie, Zoologie. ' Die zweite deutsche Polarfabrt., Zoi>loyie.

3 Die Crustaceen gesamtuelt wahrend der Fahrten des " Willem Barents " in den Jaliren 1878 und 1879.
■• Oversigt over Norges Crustaceer, i. ; and, Crustacea et Pycnogouida nova Expeditionis Norvegicae.

220 THE VOYAGE OF H.M.S. CHALLENGER.

Ecto-Paeasites (PI. XXXVIII. figs. 8-14).

All these forms belong to the Bopyridan tribe and the family Dajidte, and occur
attached in diflPerent parts of the anterior division of the body on certain Schizopoda
from the Challenger Expedition. As usual, the dwarfed males are found adhering to the
posterior part of the body of the much larger females.

The form represented in fig. 8 exhibits at the first glance, both as regards its external
apjiearance and relative position to the body of the Schizopod, to which it is attached, a
striking resemblance to the Norwegian iovm. Aspidophryxiis loeltatus, G.' 0. Sars. Never-
theless, it cannot properly be referred even to the same genus, since the clasping legs
are not, as in that genus, crowded together anteriorly at the sides of a very restricted
median area, but are found arranged along the lateral edges of the body, the four anterior
pairs occurring ut the sides of the anterior half, whereas the posterior pair originate far
behind the rest, near the posterior extremity of the body. This posterior pair of legs
would seem, moreover, to exhibit a very peculiar structure, having the aspect of two
rather large posteriorly directed appendages, bifurcate at the extremity. The body is
distinctly segmented along the median part, and mottled there -with densely crowded
pigment spots, whereas the greatly expanded and vaulted lateral parts are quite
smooth and pellucid, admitting of the ovaries, with their numerous ova, to be distinctly
ti'aced through their waUs. The male (see fig. 8, h) is seen adhering to the posterior end
of the body of the female, or the rudimentary tail, and would seem to agree in structure
with that of Asimlopkryxiis. The above recorded parasite was found on a specimen of
Euphausia peUucida, Dana, taken ofi' Cape Verde Islands, April 26, 1876, and was
mounted, together with the Schizopod itself, in Canada balsam on a glass slide. It may
properly be named Heterophryxus appendiculatus, n. gen. et sp.

The two forms represented in figs. 9, 10, 11 would seem, as regards their general
structure, to agree tolerably well with the species of the genus Notophryxus, Gc. 0. Sars,
the body being sac-like, with but very slightly indicated segmentation, and with the
five pairs of clasping legs crow^led together in the anterior part of the ventral face, at
the sides of the oral area (see fig. 10). One of the forms (figs. 9, 10) has, however, a
rather anomalous position on the Schizopod, not being, as usual, attached to the dorsal
face but to one of the sides of the body, or, more precisely, to the base of the penultimate
gill, for which reason it may properly be named Notophryxiis latercdis, n. sp. It
was found on two specimens of Nematoscelis megalops, G. 0. Sars, taken in the South
Atlantic, March 9, 1876. The other form (fig. 11) was found attached to the posterior
part of the dorsal face of the carapace on a specimen of Thysanoessa gregaria, G. 0. Sars,
taken July 10, 1875, in the North Pacific. Cwiug to its comparatively short and thick-
set body, this form may be termed Notophryxus globularis, n. sp.

The fourth form, finally (figs. 12, 13, 14), evidently belongs to the genus Dajvs.

REPORT ON THE SCHIZOPODA. 221

Kroyer, thougli unquestionably distinct from the Arctic form Dajus raysidis, Kroyer.
The adult female (figs. 12, 13) has, in its external apijcarancc, a very striking similarity
to certain jDarasitic Copepoda, the anterior division of the body being greatly expanded
and of a rounded triangular form, with a sHghtly indicated segmentation, whereas the
posterior part, or tail, is abruptly narrowed, more distinctly segmented, and terminates
in two simple lamelliform appendages, reminding one of the so-called furca of the
Copepoda. The five pairs of clasping legs are (see fig. 13) crowded together on either
side of the buccal area, which occupies about the centre of the ventral face of the anterior
division. The male (figs. 12, 13, a, 14) difi'crs, as in the typical species, materially from
the males of the preceding forms, in having the tail distinctly segmented and furnished
with well-developed pleopoda, as also with a pair of biramous uropoda. It is found with
its anterior part deeply immersed in a hollow space of the female, lying ventrally at
the end of the anterior division, and partly defined by two wing-like, posteriorly pointing
cuticular folds (see fig. 13), the remaining part of its body projecting freely behind in the
same axis as that of the female. Both the female and the male, but more especially
the latter, are variegated with dark pigment deposits over their dorsal face. This
peculiar form was found attached to the ventral fiice of the trunk posteriorly on a few
specimens of Siriella thompsoni (Milne-Edwards), both males and females, in the latter
lying 'partly within the marsupial pouch, as was also the case with Dajus mysidis. It
may justly be named Dajus siriellce, n. sp.

Endo-Parasites (PI. XXXVIIl. figs. 1 5-23).

The two forms of parasites treated on under this head were both found within the
body cavity of certain Euphausiidaj, their bodies freely suspended in the peri^•isceral
fluid of the Schizopods, and not covered by any particular envelope or cyst. They
evidently belong to two diff'erent groups of intestinal worms, the one l)eing an Acantho-
cephalan, the other a Trematode. Concerning both, I have thought it right to consult
the celebrated German Professor Rudolf Leuckart, unquestionably the greatest authority
as regards intestinal worms, and he has most cordially given me his suggestions respecting
the present interesting forms. None of them can, according to Professor Leuckart, be
reo-arded as sexually mature, but represent a mere transitory stage, that probably does
not arrive at full maturity, before being transferred into the intestinal canal of some
higher animals, most likely fishes or whales, which arc both known to feed largely upon
Euphausiida3. In their present stage of development they simply absorb through the
skin the perivisceral fluid, in which their bodies are suspended, and are thus placed under
particularly favourable conditions of life, whence their comparatively large size, in pro-
portion to the size of the Schizopods infested by them.

The form represented in figs. 15-18 is readily recognised as a species of the genus

222 THE VOYAGE OF H.M.S. CHALLENGER.

Echinorhynckus, Miiller, more especiiiUy by the cylindrical proboscis (see fig. 17), pro-
truding from the ventral face of the anterior extremity, and armed with numerous
strongly chitinised recurved hooks (fig. 18). The body (see fig. 16) is rather elongate
and somewhat flattened, irregularly wrinkled transversely, and o1:)tusely rounded at
both ends. It was found within the body cavity of a specimen of Exiphausia j^ellucida,
Dana, occupying the greater part of its length, and bent, moreover, in the form of the
letter S (fig. 15). The species may, on account of its irregularly wrinkled body, be
properly named Echinorhynchus corrugatus, n. sp.

The other form (figs. 19-23) exhibits a very peculiar appearance, but may neverthe-
less be undoubtedly determined as a species of the genus Distomum, Zed., since it
presents two well-defined sucking disks, the one anterior, or oral, the other ventral. The
body is not, as usual, flattened, but cylindrical and twisted in a peculiar manner, having,
moreover, the ventral sucking disk mounted at the end of a cylindrical peduncle that
stands out at right angles from the body. The integument is rather firm and muscular,
as also densely wrinkled transversely throughout its anterior half, but rather pellucid, so
as to admit of the two spirally twisted intestinal caeca being distinctly traced within the
body. The most peculiar feature of this form is, however, the mode in which it is
aflixed within the body cavity of the Schizopod. For this is not efi'ected by any of the
sucking disks, but with the aid of a kind of byssus excreted from the posterior end of
the animal and dispersed within a peculiar sac-like body, lying transversely within the
posterior part of the body cavity of the Schizopod (see fig. 19), and at least with one of
its extremities firmly connected with the outer skin, thus often producing a conspicuous
mamiUiform projection behind the posterior gill (see PL XXIII. fig. 10). Whether this
peculiar body ought to be referred to the parasite itself, or possibly should be regarded
as a pathological product of the Schizopod, is still uncertain. On opening the body just
mentioned, the byssus is found toconsist of two rather strong filaments (see figs. 21, 22),
more or less twisted upon themselves, as a rope, and of a number of very fine and
highly adhesive fibres (fig. 23), partly curled up in globular masses, and partly stretching
along the two filaments. The slightest touching of the byssus with any object will
cause such objects to adhere rather firmly thereto, even in spirit-specimens. This
very peculiar intestinal worm I found in several specimens of the two Euphausiidans,
Neviatoscelis megcdops, G. 0. Sars, and Thysanocssa gj-egaria, G. 0. Sars, from the
South Atlantic, invariably aflixed within the body cavity of the Schizopod in the same
peculiar manner, the body itself with its sucking disks being freely suspended anteriorly
within the perivisceral fluid, and, as a rule, a little asymmetrically, towards the right or
left side of the intestinal canal of the Schizopod. Professor Leuckart has proposed to
designate the species Distomum filiferum, n. sp., and will give a short account of its
structure in an Appendix to one of the forthcoming Zoological Reports.

TABLE OF CONTENTS.

Introduction, ....
Principal "Works on Schizopoda,
Terminology, ....
Morphology of the Schizopoda,
Definitions of the Families,
List of the Species, .
Description op Genera and Species,
Lophogastiidffi,

LofJiogaster, M. Sars,

Lophogaster tyincus, M. Sars,
Curatolqjh, G. O. Sars,

Ceratoleiris hamala, G. 0. Sars,
Gnatlwpliausia, Will.-Subm, .

Gfuathophauniic ingens (Dohrn),

giyas, Will.-Suhm,
calcarata, G. 0. Sars,
willemoesii, G. O. Sars,
affiiiis, G. O. Sars,
eJcgans, G. 0. Sars,
zoea, Will.-Suhm,
lorigispina, G. O. Sars,
gracilis, Will.-Suhm,
CJidlaraspis, Will.-Suhm (ex 2>arte),
Cliolaraipis alata, Will.-Suhm,
Eucopiidse,

Eucopia, Dana,

Eucopia australis, Dana, .
Eiiphausiidss,

Eapliausia, Dana,

Eupliauina pellucida, Dana,

similis, G. O. Sars,
s2)lendens, Dana,
nmrrayi, G. 0. Sars, ,
superha, Dana,
ankirrficn, G. 0. Sars,

page
1
2
3
7
10
12
la
13
U
14
17
17
20
30
33
35
38
41
42
44
46
48
50
51
53
54
55
62
63
75
79
80
82
84
86

224

THE VOYAGE OF H.M.S. CHALLENGER.

EupliausiidiB — continued.

Eupliauda rmicronata, G. 0. Sars,
gracHh; Dana,
gibba, G. O. Sars,
spinifera, G. O. Sars,
latifrons, G. 0. Sars,
Thysanopoila, M.-Edwards, .

Thysanopoda tficuspidata, M.-Edwards,
oMusifrons, G. O. Pars,
crisfafa, G. O. Sars,
microphthalma, n. sjj.,
BcntheuiiJtaiisia, n. gen.,

Bentheuphausia amblyops, G. O. Sars,
Nydipihanes, G. O. Sars,

Nyctip)lianes aiistralis, G. 0. Sars,
Tlvjsanoessa, Brandt, .

Tliysanoessa ijregaria, G. O. Sars,
maerura, G. O. Sars,
Nemafosceljx, G. 0. Sars,

Ncmatoscelis megalops, G. 0. Sars,
microps, G. 0. Sars,
tenella, G. O. Sars,
rostrata, G. O. Sars,
Styloeheiron, G. O. Sars, .

Styloeheiron carinatum, G. O. Sars,
suhmii, G. 0. Sars,
longieorne, G. O. Sars,
elongatum, G. O. Sars,
ahhreviatum, G. O. Sars,
Development of Euphadsiid*,

Early Larval Stages of Nyctiphanes australis, G. O. Sars,
Development of Eupihauma pellucida, Dana, .

A. General Description of the successive Larval Stages,

B. Development of the several Appendages of the Body,
Development of Thysanopoda tricuspidata , M.-Edwards,
Development of Nematoscelis rostrata, G. 0. Sars,
Larval Stage of EuphausuL sp. (?),

Mysidje, .....
Petalopldhalmus, Will.-Suhm,

Pefalopjhthalmus armiger, Will.-Suhm,
Boreomysis, G. 0. Sars,

Boreomysis scyphops, G. 0.,Sars,
oUusata, G. 0. Sars, .
microps, G. 0. Sars, .
A)nblyo])s, G. 0. Sars,

AinUyoi^s crozetii, Will.-Suhm MS.,

PAGE

87
89
91
93
95
97
98
102
104
106
108
109
114
115
119
120
125
120
127
131
133
135
136
137
142
144
146
147
149
150
155
156
158
165
169
170
172
173
174
177
178
182
184
186
186

REPORT ON THE SCHIZOPODA.

225

Mysidae — continued.

PAOE

Pseudomma, G. 0. Sars, . . . . . . . .188

Pseudomma sarsii, Will.-Suhiii MS.,

189

atistralf, G. 0. Sara,

191

Anchialtts, Krbyer, .....

192

Anchiahis typicu^, Kroyer,

193

angustus, G. 0. Sars, .

197

pmillus, G. 0. Sars, .

200

Mysidopsis, G. 0. Sars, ....

201

Mysidopsis iiicisa, G. 0. Sars, ...

202

Siriella, Dana, .....

204

Siriella fhompsoni (M. -Edwards),

205

gracilis, Dana, .....

209

Euchaetomera, G. 0. Sars, .....

211

Euchoetomera typica, G. 0. Sars,

211

tenuis, G. 0. Sars, ....

214

Heteromysis, Smith, ......

216

Eetemmysis bermudensis, G. 0. Sars,

216

Appendix, . . . . .

219

Notes on some Parasites obtained from the Challenger Specim

ens of Schizopoda,

219

Ecto-Parasites, .....

220

Endo-Parasites, ......

221

(ZOOL. CHALL. EXP. PABT XXXVII.— 1886.)

Oo29

INDEX OF SYSTEMATIC NAMES.

(Synonyms and Species incidentally mentioned are in italics.)

Acanthocephalan, 221.
Amblyops, 186.

abhrevicUa, 186.
atistralis, 191.
crozetii, 186.
Ancliialus, 192.

agilis, 192.
angnstus, 197.
pusUlus, 200.
truncatus, 193.
typicus, 193.
Anomobranchiata, 7.
Aspidophryxus, 219, 220.

peltatus, 220.
Bentheuphausia, 108.

amblyops, 109.
Boreomysis, 177.

ardica, 177.
megalops, 178.
microps, 184.
nobilis, 178.
obtusata, 182.
scyphops, 178.
tridens, 178.
Boreophausia, 64, 74.
Caridea, 7.

Calyptopis, 150, 152, 154, 155, 156, 166.
Ceratolepis, 17.

liamata, 17.
Chalaraspis, 50, 54.

alata, 51.

nnguiculata, 53, 55.
Chiromysis, 216.
Cfenomysis, 14.

alata, 14.
Cynthia, 204.

inermis, 205.
thompsoni, 205.
Cyrtopia, 150, 157, 158, 167, 170.

Dajus, 221.

mysidis, 219, 221.
sirielte, 221.
Decapoda, 7.
Distomum, 222.

filiferuni, 222.
Ecto-Parasites, 220.
Echinorhynchus, 222.

corrugatus, 222.
Endo-Parasites, 221.
Ephyridae, 8.
Erythrops, 211.
Eubrancbiata, 7.
Eucha;tomera, 211.

tenuis, 214.
typica, 211.
Eucopia, 54.

australis, 55.
equatoria, 55.
Eucopiidse, 10, 53.
Euphausia, 63.

antarctica, 86.
gibba, 91.
gracilis, 89.
latifrons, 95.
mucronata, 87.
miilleri, 75, 78.
murrayi, 82.
pellucida, 75, 155.
simUis, 79.
spinifera, 93.
splendens, 80.
superba, 84.
Euphausiidae, 10, 62, 149.
FurciJia, 150, 156, 157, 167, 169, 170.
Gnathophausia, 20.

affinis, 41.
calcarata, 35.
elegans, 42.

228

THE VOYAGE OF H.M.S. CHALLENGER.

Gnathophausia gigas, 33, 35.
gracilis, 48.
inflnta, 30.
ingens, 30.
longispina, 46.
willcmoesii, 38.
zoiia, 38, 44.
Heteromysis, 216.

bermudonsis, 216.
formosa, 216.
microps, 216.
noroerjica, 216.
Heterophryxus, 220.

appendiculatus, 220.
Leptophryxiis, 219.
Leucifer, 7.
Lophogaster, 14.

typicus, 14.
ingens, 30. •
Lophogastridae, 10, 13.
Macrura, 7.
Metanauplius, 1.50.
Mysidopsis, 201.

anijusta, 202.
didelphys, 202.
gibbosa, 202.
incisa, 202.
Mysidas, 11.
Mysis, 202.

moebii, 193.
oculata, 219.
relida, 181.
Nauplius, 149.
Nebalia, 9.
Nematoscelis, 126.

megalops, 127.
microps, 131.
rostrata, 135, 169.
tenella, 133.
Notophryxus, 219, 220.

lateralis, 220.
globularis, 220.
Nyctiphanes, 114.

australi.s, 115, 150.
norvrgica, 115.
Paranebalia longipes, 217.
Parasites, 219.
Pasiphaidse, 8.
Peiiaeidea, 7, 8.
Petalophthalmus, 173.

Petalophthalmus armiger, 174.
inermis, 178.
Phyllooarida, 9.
Podoplithalmia, 7, 8.
Post-Larval Stage, 150, 158, 168.
Promyids, 200, 202.

galathecK, 205.
pusilla, 200.
Pseudomma, 188.

affinr, 189.
australe, 191.
roseum, 189.
sarsii, 189.
fruncatum, 189.
Schizopoda, 7, 8, 9, 13.
Sergestes, 7.
Siriella, 204.

brevipes, 205.
edwardsii, 205.
gracilis, 209.
thompsoni, 205.
vitrea, 205.
SpJiceronella leuckartii, 219.
Squillacea, 7.
Stomatopoda, 7.
Stylocheiron, 136.

abbreviatum, 147.
carinatuin, 137.
elongatum, 146.
longicorne, 144.
suliinii, 142.
Thysanoessa, 119.

borealis, 120.
gregaria, 120.
longipes, 120.
macrura, 125.
tenera, 120.
Thysanopoda, 97.

amblyops, 109.
bidentata, 75, 77.
cristata, 104.
couchii, 115.
inermis, 64.
longicaudata, 64.
micropbthalma, 106.
negleda, 64.
norvegica, 115.
■ obtusifrons, 102.
tricuspidata, 98, 165.
Trematode, 221.

PLATE I.

(ZOOL. CHALL. EXP. PART XXXVII. — 1885.) — Oo.

PLATE I.

Figs. 1-7. Lophogaster typictis, M. Sars.

Fig. 1. Adult male, from left side ; magnified about five times.

Fig. 2. Female, from above.

Fig. 3. Anterior part of carapace of male, along with eyes, antennulse and antennae,
viewed from above.

Fig. 4. Basal part of a female antenna, with antenna! scale and proximal section of
flagellum, from below.

Fig. 5. Leg of last pair.

Fig. 6. Posterior extremity of tail, with caudal fan, from above.

Fig. 7. Extremity of telsou ; more highly magnified.

Figs. 8-17. Ceratolepis hamata, G. 0. Sars.

Fig. 8. Female, from left side ; magnified about ten times.

Fig. 9. Same, from aliove.

Fig. 10. Anterior part of carapace, with eyes, from above ; somewhat more magnified.

Fig. 11. Anterior part of body, viewed from the ventral face, showing antennulse («'),
antennae («-), antennal scale (sq), anterior lip (i), mandibles (if), mandibular
palps (p), second pair of maxillae {ni'), maxillipeds {mp'), with their rudi-
mentary exopodite {x).

Fig. ] 2. Base of an antenna, with antennal scale.

Fig. 13. One of the gnathopods.

Fig. 14. One of the legs.

Fig. 15. Posterior pair of legs, with the corresponding pair of incubatory lamellae and
the rudimentary exopods.

Fig. 16. A caudal epimeron, lateral aspect.

Fig. 1 7. Extremity of tail, with caudal fan, from above.

Note. — The figures on all the plates have been drawn by the author with the aid of the camera lucida.

The VovaiSe of "H, M SfChallenga"

& 0. Sars,del.

Lith.'WScHaAt-

Figs 1-7, LOPHOGASTER TYPICUS.M Sars
„ 8 17, CERATOIEPIS HAMATA^ngen isp.

PLATE II.

PLATE 11.

Chiathophausia ingens (Dohrn).

Fig. 1. Adult female, from right side ; natural size.

Fig. 2. Same, from above.

Fig. 3. An eye.

Fig. 4. Antenna, with scale and proximal part of flagellum.

Fig. 5. One of the legs.

Fig. 6. The two last segments of tail, together with basal parts of uropoda, from below
exhibiting the peculiar epimeral plates of last segment.

Fig. 7. Extremity of tail, with caudal fan, from above.

The Voyage of H. M S.'Cliallenger"

Schizcnoda,?: II

" ii.

u. J. idrs. 'lei

LiUlW.;i.

GNATHOPHAUSIA INGENS (Dohrn)

PLATE III.

(ZOOL. CnALL. EXP. PART XXXVII. — 1885.) — Oo.

PLATE III.

Gnathophausia gigas, Willemoes-Suhm.
Fiff. 1. Adult male, from left side ; natural size.
Fig. 2. Same, from above.
Fig. 3. An eye.
Fig. 4. Antenna, with scale and flagellum.

Fig. 5. Last caudal segment, with basal parts of uropoda, from l)elow, exhibiting the
confluent epimeral plates.

Fig. 6. Extremity of tail, with telson and right uropod, from above.
Fio-. 7. Tip of telson ; somewhat more magnified.

'P'^o ^/'ni- ..«.., ^-r TI T,," C ","1,t11„„>

G. 0. Sars.del

lithWSchlac!

GNATHOPHAUSIA GIGAS, Wiliem Suhm.

PLATE IV.

PLATE lY.

Gnathophcmsia calcarata, G. 0. Sars.

Fio;. 1. Adult male, from right side ; very slightly magnified.

Fig. 2. Same, from above.

Fig. 3. Carapace of another somewhat smaller specimen, from below, a, supra-orbital
spines (1) ; h, antennal spines ; c, branchiostegal spines.

Fig. 4. Anterior part of body, from below, exhibiting eyes, antennulse («',), antennae (a^,
anterior lip (L), mandibles {M), mandibular palps {Mp), second pair of
maxillse {m~), with their exognaths (^), and the pigmented basal protuber-
ance (ic), maxillipeds {mp'), with their rudimentary exopodite {p).

Fig. 5. Antenna, with scale and proximal part of flagellum.

Fig. 6. Last caudal segment, from below, exhibiting the confluent epimeral plates.

Fig. 7. Extremity of tail, with caudal fan, from above.

The Voyage of H M. S.'CMle

Lri-WSchl-

GNATHOPHAUSIA CALCARATA.n sp

PLATE V.

(ZOOL. CHALL. EXP. — PART XXXVII. 1885.) — Oo

PLATE V.

Figs. 1-6. Gnathophansia willemoesii, G. 0. Sars.

Fig. 1. Adult female, from left side; natural size.

Fig. 2. Same, from above.

Fig. 3. An eye.

Fig. 4. Antenna, with scale and flagellum.

Fig. 5. The two last ca.udal segments, with basal parts of uropoda, from below.

Fig. 6. Telson, from above.

Figs: 7-10. Gnathophausia affinis, G. 0. Sars.
Fig. 7. Female, from right side ; slightly magnified.
Fig. 8. Same, from above.

Fig. 9. Antenna, with scale and proximal part of flagellum.
Fig. 10. Extremity of tail, with telson and right uropod, from above.

The Voyage ofH. M S." Challenger"

Schizopoda^Ii V

/ iruJ a.

G. 0. Sars.del.

Jjith.'W ochlackat Sr

Fig5l_G,GNATH0PHAUSlA WILLEMOESII , n cp
„ 7_10, „ AFFINIS.nsp

PLATE VL

PLATE VI.

Figs. 1-5. Gnathophausla elegans, G. 0. Sars.
Figf. 1. Female, from left side ; magnified about three times.
Fig. 2. Same, from above.

Fig. 3. Antenna, witli scale and proximal part of flagellum.
Fig. 4. Telson, from above.
Fig. 5. Extremity of same ; more liighly magnified.

Figs. 6-10. Gnathophausia zoea, Willemoes-Sulim.

Fig. 6. Adult female, from right side ; twice the natural size.

Fig. 7. Same, from above.

Fig. 8. Anterior part of carapace, with base of rostrum, from below, a, supra-orbital
spines ; b, antennal spines ; c, branchiostegal expansions.

Fig. 9. Antenna, with scale and proximal part of flagellum.

Fig. 10. Extremity of tail, with telson and right uropod, from above.

The Voyaf^e of H, M S.' Challenger"

. Sars, del.

lifli-WScWacl

Fig! 1_5,GNATH0PHAUSIA ELEGANS, n sp
„ 6_10, „ ZOEA,Willem Suhm

PLATE VII.

(ZOOL. CHALL. EXP. PART XXXVII. 1885.) — Oo

PLATE VII.

Figs. 1-5. Gnathophausia longispina, G. 0. Sars.

Fig. 1. Adult male, from left side ; magnified about three times.

Fig. 2. Same, from above.

Fig. 3. Antenna, with scale and proximal part of flagellum.

Fig. 4. Extremity of tail, with telson, from above.

Fig. 5. Anterior part of carapace, with base of rostrum, from below, a, supra-orbital
spines ; 6, rudiments of antennal spines ; c, branchiostegal spines.

Figs. C-10. Gnathophausia gracilis, Willemoes-Suhm.
Fig. 6. Male, from left side ; magnified about three times.
Fig. 7. Same, from above.

Fig. 8. Antenna, with scale and proximal part of flagellum.
Fig. 9. Extremity of tail, with telson and right uropod, from above.
Fig. 10. Tip of telson; more highly magnified.

I'he Voyage of H. M S/'Challer.sie

Bchizopoda.Pl.'VII.

C-. 0. 3ars, del.

lith'WScHaclitet StocHiolnL

Fig? 1_5,GNATH0PHAUSIA LONGISPlNA.n sp
„ 6_10^ „ GRACILIS, WillemSuhm

PLATE YIII.

PLATE VIII.

Gnathophausia longispina, G. 0. Sars.

(Anatomy).

Fig. 1. Ocular segment, with right eye (o) and right antennular peduncle, from above.

Fig. 2. Anterior lip {L) and mandibles with their palps, from below:

Fig. 3. Terminal joint of mandibular palp ; more highly magnified.

Fig. 4. Cutting edges of mandibles.

Fig. 5. Posterior lip.

Fig. 6. Maxillae of first pair, with palp.

Fig. 7. Maxillae of second pair. ^), palp ; ex, exognath ; x, pigmented basal pro-
tuberance.

Fig. 8. Maxilliped. x, concave surface occurring in place of the exopodite ; ej),
epipodite.

Fig. 9. Leg of first pair, or gnathopod, with attached gill.

Fig. 1 0. Leg of second pair, ep, rudimentary epipod.

Fig. 11. Bases of a pair of legs, with the attached gills in situ.

Fig. 12. Gill, isolated.

Fig. 1.3. Extremity of a gill-branch ; more highly magnified.

Fig. 14. Leg of last pair, with male sexual aperture (p) and the rudimentary gill (hr).

Fig. 15. Male sexual aperture ; more highly magnified.

Fig. 16. Trunk, with maxillipeds, legs, and gills in situ, viewed from the ventral face.

Fig. 17. Trunk, together with first caudal segment and oral parts, from right side. The
carapace is removed to show the seven segments of the trunk with their gdls.
L, anterior lip ; M, mandible ; p, mandibular palp ; m', maxilla of first pair ;
m'", maxilla of second pair ; x, pigmented basal protuberance of same ;
mp', maxilliped ; ep, epipodite of same ; mp^, leg of first pair or
gnathopod.

Fig. 18. A pleopod.

Fig. 19. Chaiii of ventral ganglia; 1-9 those belonging to anterior division, following
(l-G) caudal.

Fig. 20. Part of the anterior division of the chain, together with the great ventral artery
(a) ; more highly magnified.

The Voyage of H. M S." Challenger"

Schizopoda.Pl.Vni.

aO.Sars.dd.

lift-WScUachtei: StocHioln'.

GNATHOPHAUSIA LONGISPINA.
(Anatomy)

PLATE IX.

(ZOOL. CHALL. EXP. — PAET XXXVII. 1885.) — Oo.

PLATE IX.

Eucopia austrahs, Daua.

Fig. 1. Adult female with marsupial pouch, from right side ; magnified about three
times. The exterior parts of the four posterior pairs of legs were
broken off.

Fig. 2. Same, from above.

Fig. 3. Ocular segment, with left eye and antennular peduncles, from above.

Fig. 4. Antenna, with scale and proximal jiart of flagellum.

Fig. 5. Anterior lip and mandibles iti situ, from below.

Fig. 6. Masticatory parts of mandibles, exhibiting the armature of the cutting edges.

Fig. 7. Last joint of mandibular palp.

Fig. 8. Posterior lip.

Fig. 9. Maxilla of first pair.

Fig. 10. Extremity of outer masticatory lobe of same ; more highly magnified.

Fig. 11. Maxilla of second pair.

Fig. 12. Maxilliped, with the rudimentary exopodite and greatly developed epipodite.

Fig. 13. Extremity of endopodite of same ; more highly magnified.

Fig. 13 (bis). Leg of first pair, or first gnathopod, with attached giU.

Fig. 14. Gill of same, isolated and more highly magnified.

Fig. 15. Leg of second pair, or second gnathojsod, with attached gill and incubatory
lamella.

Fig. 16. Extremity of same ; more highly magnified.

Fig. 17. Leg of thii'd pair, or third gnathopod.

Fig. 18. Exti'emity of same ; more highly magnified.

Wr S'Challen^er"

Schizopoda,Pl EC.

Liffi-".'," Tr r"= r-nier SiodKhorji.

EUCOPIA AUSTRflLIS, Dana.

PLATE X.

Eucopia australis, Dana.

(Continued).

Fig. 1. Young female, with all its limbs uninjured, from left side ; magnified about four
times.

Fig. 2. Trunk, from left side, with attached limbs ; carapace removed to show the
segments and gills, ep, epipodite of maxilliped.

Fig. 3. Extremity of a gill-branch.

Fig. 4. One of its lobes ; highly magnified.

Fig. 5. Leg of fourth pair, with attached gill.

Fig. 6. Exti-emity of same ; more highly magnified.

Fig. 7. Extremity of a leg of last pair.

Fig. 8. A pleopod.

Fig. 9. Extremity of tail, with telson and left uropod, from above.

Fig. 1 0. Tip of telson ; more highly magnified.

Fig. 11. Exterior corner, with part of apical edge of outer plate of uropod.

Fig. 12. Part of the nervous cord, comprising seven ganglia of the trunk and three
caudal.

Fig. 13. Cephalic part of body of a male specimen, with eyes, antennulse and antennae,
from above.

Fig. 14. Anterior part of body of same, from below. L, anterior lip ; M, mandibles ;
Mp, mandibular palp ; I, posterior lip ; mp, maxilliped. The limbs behind
the mandibles are only represented on the right side.

Fig. 15. A gill-branch of same.

Fig. 16. One of the posterior gnathopodous legs of same.

Fig. 17. A male pleopod.

i:illen|er"

„ ^^

-'. iiars.del.

EUCOPIA AUSTRALIS, Dana.

PLATE XI.

(ZOOL. CHALL. EXP. PART XXXVII. 1885.) Oo.

fe^s

PLATE XL

Euphausia pellucida, Dana.

Fig. 1. Adult female, from right side ; magnified about nine times.

Fig. 2. Same, from above, showing the luminous globules shining through the
integument.

Fig. 3. Preanal spine ; highly magnified.

Fig. 4. Adult male, from left side.

Fig. 5. Anterior part of body of a female specimen, together with fii'st caudal segment,
from right side, showing the internal organs shining through the carapace.
st, stomach ; I, liver ; i, intestine ; h, heart ; ov, ovary ; ovd, oviduct.

Fig. 6. Carapace, with eyes, antennular peduncles ; antenna3, anterior lip (L), mandibles
{M), mandibular palps (il^j), and heart (/i), from below.

Fig. 7. Ocular segment, with left eye, from below, a, larval eye or ocellus ; &, luminous
organ.

Fig. 8. Luminous organ of ocular pedicle, isolated and highly magnified.

Fig. 9. Gill of antepenultimate pair, with the bulbous basal expansion containing a
luminous globule.

Fig. 10. The latter part; more highly magnified.

Fig. 11. Gill of last pair.

Fig. 12. Eudiment of a leg of penultimate pair ; highly magnified.

n. M.S." Challenger"

EUPHAUSIA PELLUCIDA,Dana

PLATE XII.

Euphausia pellucida, Daua.
(Anatomy — continued. )

1. Right autciinular peduncle, from above.

Same, from inuer side.

Dorsal leaflet of same ; highly magnified.

Dorsal leaflet of another specimen, exhibiting numerous pointed lappets.

Left antenna, with scale and proximal part of flagellum, from below.

Same, from the outer side.

Anterior lip.

Posterior lip.

Mandible.

Masticatory parts of mandibles, more highly magnified, exhibiting the arma-
ture of the cutting edges.

Mandibular palp.

Maxilla of first pair.

Maxilla of second pair.

Maxilliped.

Fig. 15. Extremity of same ; more highly magnified.
Fig. 16. Leg of first pair, with attached gill.
Fig. 17. Terminal joint of same ; more highly magnified.
Fig. 18. Leg of second pair, with attached gill.
Fig. 19. Leg of antepenultimate pair, with attached gill.
Fig. 20. Gill of third pair.
Fig. 21. Gill of fourth pair.

Fig. 22. Extremity of a gill-stem, with seven of the digitiform lobules, highly magnified.
Fig. 23. Spermatophore found affixed to the genital orifice of a female specimen.
Fig. 24. A pair of pleopods of a female specimen, with the luminous organ projecting

between their bases.
Fig. 25. Inner branch of a pleopod, without the marginal setse.
Fig. 26. Luminous globule from the tail, isolated and highly magnified.
Fig. 27. Extremity of taU, with telson and right uropod, from below.
Fig. 28. Inner branch of a male pleopod of first pair, exhibiting the peculiar copulatory

appendages.
Fig. 29. Inner branch of a male pleopod of second pair.

Fig. 30. Central part of the nervous system (nervous cord), with all the ganglia in their
natural connection with each other, from below.

Fig.

Fig-

Fig.

Fig-

Fig.

10.

Fig.

11.

Fig-

12.

Fig.

13.

Fig.

14.

The Voyage cf H. M. S." Challenger"

icliizor.oda.'FlXn.

EUPHAUSIA PELLUCIOA,Dana .

(Anatomy).

LvJl

PLATE XIII.

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oo.

PLATE XIII.

Figs. 1-6. Euphausia similis, G. 0. Sars.

Fig. 1. Adult male, from right side ; magnified about six times.

Fig. 2. Anterior extremity of body, with eyes, antennulse and antennae, from above.

Fig. 3. Inner plate of a male pleopod of first pair.

Fig. 4. Inner plate of a male pleopod of second pair.

Fig. 5. Extremity of tail, with caudal fan, from above.

Fig. 6. Extremity of last caudal segment, with base of telson and uropods, from right
side, more highly magnified, showing the simple preanal spine.

Figs. 7-17. Euphausia splendens, Dana.

Fig. 7. Adult female with spermatophores, from right side; magnified about seven
times.

Fig. 8. Eight antennular peduncle, from above.

Fig. 9. Eioht antenna, from below.

Fig. 10. Mandibular palp.

Fig. 11. Maxilla of first pair

Fig. 1 2 Maxilla of second pair

Fig. 13. Inner plate of a male pleopod of first pair.

Fig. 14. Inner plate of a male pleopod of second pair.

Fig. 15. Anterior part of body, from above.

Fig. 16. Extremity of tail, with caudal fan, from above.

Fig. 17. Preanal spine.

The Voyage of H. M. S." Challenger"

^^V-~,v --)-

aO.Sars.del.

Litk'W: ScMacltta: Stockholm.

Figs 1_e, EUPHAUSIA SIMILIS.nsp
„ 7_17 „ SPLENDENS Dana

PLATE XIY.

PLATE XIV.

Figs. 1-4. Eujyhausia murrayi, G. O. Sars.
Fig. 1. Female, from right side ; magnified about four times.
Fig. 2. Anterior part of body, from above.
Fig. 3. One of the anterior gills.
Fig. 4. Extremity of tail, with caudal fan, from above.

Figs. 5-9. Euphausia siqyerha, Dana.
Fig. 5. Adult male, from right side ; magnified about four times.
Fig. 6. Anterior part of body, from above.
Fig. 7. Inner plate of a male pleopod of first pair.
Fig. 8. Inner plate of a male pleopod of second pair.
Fig. 9. Extremity of tail, with caudal fan, from above.

'&U

W'M J

( v vj

■7i-i V.-Jf:

J V

,''A\

V4)>

U-Il^V. ScKachte

Figs 1 _4, EUPHAUSIA MURRAYIn sp
5_9 „ SUPERBA Dana

PLATE XV.

(ZOOL. OHALL. EXP. PART XXXVII. — 1885.) — Oo

PLATE XV.

Figs. 1-8. Euphausia antarctica, G. 0. Sars.

Fio'. 1. Female, from right side ; magnified about eight times.

Fig. 2. Anterior part of body, from above.

Fif. 3. Extremity of tail, with caudal fan, from above.

Fig. 4. Preanal spine.

Fig. 5. Mandibular palp.

Fig. 6. Maxilla of first pair.

Fig. 7. Maxilla of second pair.

Fig. S. Leg of antepenultimate pair, with attached gill.

Figs. 9-11. Eujjhausia mucronata, G. 0. Sars.

Fig. 9. Adult female, from left side ; magnified about ten times.

Fig. 10. Anterior part of body, from above.

Fio-. 11. Extremity of tail, with caudal fan, from above.

Figs. 12-23. Euphausia gracilis, Dana.

Fig. 12. Adult male, from right side ; magnified about twelve times.

Fig. 13. Eight antennular peduncle, from above.

Fig. 14. Left antenna, from below.

Fig. 15. Mandibular palp.

Fig. 16. Maxilla of first pair.

Fig. 17. Maxilla of second pair.

Fig. 18. GiU of last pair.

Fig. 19. Preanal spine.

Fig. 20. Anterior part of body, from above.

Fig. 21. Extremity of tail, with caudal fan, from above.

Fig. 22. Inner plate of a male pleopod of first pair.

Fig, 23. Inner plate of a male pleopod of second pair.

"ChallCTiger"

:,i:aTv ^."cKac:.

Figi 1_8. EUPHAUSIA ANTARCTICA, nsp Fig! 9_11. EUPHAUSIA MUCRONATA,nsp.
fip 12_23, EUPHAUSIA GRACILIS, Dana

PLATE XYI.

PLATE XVI.

Figs. 1-8. Eiqoliausia gibha, G. 0. Sars.

Fig. 1. Adult male, from left side ; magnified about ten times.

Fig. 2. Anterior part of body, from above.

Fig. 3. Extremity of tail, with caudal fan, from above.

Fig. 4. Rudimentary dorsal lobe of antenuular peduncle ; liigbly magnified.

Fig. 5. Left antenna, from below.

Fig. 6. Inner plate of a male pleopod of first pair.

Fig. 7. Inner plate of a male pleopod of second pair.

Fig. 8. Gill of last pair.

Figs. 9-16. Eupliausia spinifera, G. 0. Sars.

Fio-. 9. Adult male, from right side ; magnified about six times.

Fig. 10. Anterior part of body, from above.

Fig. 11. Extremity of tad, with caudal fan, from above.

Fig. 12. Dorsal lobe springing from basal joint of antennulas ; highly magnified.

Fio-. 13. Spine-like dorsal lobe from second joint of antennulte.

Fig. 14. Inner plate of a male pleopod of first pair.

Fig. 15. Inner plate of a male pleopod of second pair.

Fig. 16. Preanal spine.

Figs. 17-23. Eupliausia latifvons, G. 0. Sars.

Fig. 17. Male, from right side ; magnified about twenty times.

Fig. 18. Anterior part of body, from above.

Fig. 19. Middle part of left antennular peduncle, from above, showing the dorsal lobe

and the spine issuing from outer corner of basal joint.
Fig. 20. Inner plate of a male pleopod of first pair.
Fig. 21. Inner plate of a male pleopod of second pair.
Fig. 22. Extremity of tad, with caudal fan, from above.
Fig. 23. Tip of telson ; more highly magnified.

•]■!,:. '!■..■ ■.^^ n+'-p M :;"('"ha]lenger"

^ 3 T.1 'I'tl

. Sars.del.

lithW ScHactee:

Figs 1_8, EUPHAUSIA GIBBA, n sp. Figs 9JB. EUPHAUSIA SPINIFERA, n sp
Flg5l7_23, EUPHAUSIA LATIFRONS, n sp

PLATE XVIL

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oo.

PLATE XVII.

Tfiysanopoda tricuspidata, Milne-Edwards.

Fig. 1. Adult female, from left side ; magnified about six times.

Fig. 2. Anterior part of body, from above.

Fig. 3. Extremity of tail, with caudal fan, from above.

Fig. 3a. Tip of terminal projection of telson ; highly magnified.

Fig. 4. Preanal spine.

Fig. 5. Left antennular peduncle of a younger specimen, from above.

Fig. 6. Eight antenna, from below.

Fig. 7. Anterior lip.

Fig. 8. Posterior lip.

Fig. 9. Mandible, with palp.

Fig. 10. Maxilla of first pair.

Fig. 11. Maxilla of second pair.

Fig. 12. Maxilliped.

Fig. 12a. Terminal joint of same ; more highly magnified.

Fig. 13. Leg of first pair, Avith attached giU and luminous organ.

Fig. 13a. Terminal joint of same ; more highly magnified.

Fig. 14. Leg of second pair, with attached gill.

Fig. 15. Leg of fifth pair, with attached giU.

Fig. 16. Leg of penultimate pair, with gill and luminous organ.

Fig. 1 7. Gill of posterior pair.

Fig. 1 7a. Rudiment of leg of last pair.

Fig. 19. Epipodite of maxiUiped.

Fig. 20. Gill of first pair.

Fig. 21. Gill of second pair.

Fig. 22. Gill of third pair.

Fig. 23. Gill of fourth pair.

Fig. 24. Gill of fifth pair.

Fig. 25. Gill of sixth, or penultimate pair.

n§-

IS.

-\x

THYSANOPODA TRICUSPIDATA V-Eo-

PLATE XYIII.

PLATE XVIII.

Figs. 1-14. Tliysanopoda obtusifrons^ G. 0. Sars.

Fig. 1. Female, from left side ; magnified about six times.

Fig. 2. Anterior part of body, from above.

Fig. 3. Extremity of tail, with caudal fan, from above.

Fig. 4. Left antennular peduncle, from inner side.

Fig. 5. Left antenna, with scale and proximal part of flagellum, from below.

Fig. 6. Mandibular palp.

Fig. 7. Maxilla of first pair.

Fig. 8. Maxilla of second pair.

Fig. 9. Terminal joint of a leg of first pair.

Fig. 10. One of the anterior gills.

Fig. 11. Leg of penultimate pair, with attached gUl.

Fig. 12. Gill of posterior pair, with rudiment of leg.

Fig. 13. Inner plate of a male pleopod of first pair.

Fig. 1 4. Inner plate of a male pleopod of second pair.

Figs. 15-20. Thysanopoda crlstata, G. 0. Sars.

Fig. 15. Adult male, from right side ; magnified about three times.

Fig. 16. Anterior part of body, from above.

Fig. 17. Extremity of tail, with caudal fan, from above.

Fig. 1 8. Tip of telson ; more highly magnified.

Fig. 19. Inner plate of a male pleopod of first pair.

Fig. 20. Inner plate of a male pleopod of second pair.

' Thysanopoda obtusirostris has been \n\i in the plate by mistake.

The V>/a*e o+^ t^' M ^"Challenger"

Sclii:oT-o4a -pi IM.

iTS.del.

Fi6:-1-14,THYSAN0P0DA OBTUSI ROSTRIS, n.sp.
15-20' „ CRISTATA, n.sp.

PLATE XIX.

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oo.

PLATE XIX.

Bentheuphausia amblyops, G. 0. Sars.

Fig. 1. Young female, from right side ; magnified about eight times. The legs were
broken off in the specimen.

Fig. 2. Anterior part of body, from above.

Fig. 3. Extremity of tail, with caudal fan, from above.

Fig. 4. Eight eye, from above.

Fig. 5. Left antennular peduncle, from above.

Fig. 6. Safne, from inner side.

Fig. 7. Eight antenna, ^\^th scale and proximal part of flageilum, from below.

Fig. 8. Anterior lip.

Fig. 9. Posterior lip.

Fig. 10. Mandibles, from below. The masticatory part only is represented on right side.

Fig. 11. Left mandible, from outer face.

Fig. 12. Maxilla of first pair.

Fig. 13. Maxilla of second pair.

Fig. 14. Maxilliped.

Fig. 15. Masticatory lobe of same.

Fig. 1 6. Basal part of a leg of first pair, with attached gill.

Fig. 17. Basal part of a leg of fifth pair, with gill.

Fig. 1 8. Last pair of legs, with attached gills.

Fig. 19. Gill of first pair.

Fig. 20. Gill of second pair.

Fig. 21. Gill of third pair. Tip of inner branch broken ofi".

Fig. 22. GiU of fifth pair.

Fig. 23. Gill of sixth pair.

Fig. 24. Gill of last pair.

Fig. 25. A pleopod.

'v\,,- t;,„,- ..,•,.-. ^r

^I V ^"rhallenger"

)oda P: IJJj.

aa3.?rs,ae].

,...

)

ll*.

•.v:s

-Haclr-

BENTHEUPHAUSIA AM BLYOPS,n.gen & sp.

PLATE XX.

Nyctiphanes australis, G. 0. Sars.

Fig. 1. Ovigerous female, from left side ; magnified about eight times.

Fig. 2. Anterior division of body, together with first caudal segment of same, viewed
from the ventral face, to show the form of the double ovisac.

Fig. 3. Anterior part of body, from above.

Fig. 4. Right antennular peduncle, from above.

Fig. 5. Same, from inner side.

Fig. 6. Basal joint of same, from outer side.

Fig. 7. Right antenna, with scale and proximal part of flagellum, from below.

Fig. 8. Anterior lip.

Fig. 9. Posterior lip.

Fig. 10. Mandible, with palp.

Fig. 11. Cutting edges of mandibles.

Fig. 12. Maxilla of first pair.

Fig. 13. Maxilla of second pair.

Fig. 14. Maxilliped.

Fig. 14a. Terminal joint of same ; more highly magnified.

Fig. 15. Leg of first pair, with gill and luminous organ.

Fig. 15a. Terminal joint of same ; more highly magnified.

Fig. 16. Leg of second pair, with attached gill.

Fig. 17. Leg of fifth pair, with gill (exopod wanting).

Fig. 18. Leg of penultimate pair, with gill and luminous organ (exopod wanting).

Fig. 19. GiU of last pair, with rudiment of leg.

Fig. 20. Rudimentary leg of last pair, isolated, and more highly magnified.

Fig. 21. A pleopod.

Fig. 22. Extremity of tail, with caudal fan, from above.

Fig. 23. Tip of telson ; more highly magnified.

,,wnT,n,l= VI TT

iilactoer 310(33101:?.

NYCTIPHANES AUSTRALIS, n^en & sp.9

PLATE XXI.

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oci.

PLATE XXL

Figs. 1-7. Nyctiphanes australis, G. 0. Sars.

{^Continued.)

Fig. 1. Adult male, from right side ; magnified about eight times.

Fig. 2, Anterior part of body of same, from above.

Fig. 3. Posterior part of trunk, together with a part of first caudal segment, from above,
exhibiting the peculiar form of the posterior emargination of the carapace.

Fig. 4. Left male antenna, with scale and proximal part of flagellum, from below.

Fig. 5. Leg of penultimate pair in male, ^dth exopod and gill.

Fig. 6. Liner plate of a male pleopod of first pair.

Fig. 7. Inner plate of a male pleopod of second pair.

Figs. 8-17. TJiysanoessa gregaria, G. 0. Sars.

Fig. 8. Adult female, from left side ; magnified about seven times.

Fig. 9. Same, from above.

Fig. 10. Right eye, from anterior side.

Fig. 11. Same, from posterior side.

Fig. 12. Anterior part of body, from above.

Fig. 13. Eight antennular peduncle, from above.

Fig. 14. Same, from inner side.

Fig. 15. Left antenna, from below.

Fig. 16. Preanal spine.

Fig. 17. Anterior part of carapace of a male specimen, from above, showing the de-vaating
form of the rostral projection.

The Voyage of H. M. S." Challenger"

r;.-;.^7nT,n(k Fi.IXI,

LithW SchlachifiE -StocHiohn.

Fi6l 1-7, NYCTIPHANES AUSTRALIS, n sp S
Figf 8-17, THYSANOESSA GREGARIA, n sp.

PLATE LXIL

PLATE XXII.

Tliijsanoessa gregaria, G. 0. Sars.

(Anatomy — continued).
Fig. 1. Anterior lip.
Fig. 2. Posterior lip.
Fig. 3. Mandible.
Fig. 4. Mandibular palp.

Fig. 5. Masticatory parts of mandililes, exhibiting the armature of the cutting edges.
Fig. 6. Maxilla of first pair.
Fig. 7. MaxiUa of second paii".
Fig. 8. Maxilliped.

Fig. 9. Terminal joint of same ; more highly magnified.
Fig. 1 0. Leg of first pair, with gill and luminous organ.
Fig. 11. Leg of second pair, with attached gill.
Fig. 12. Extremity of same ; more highly magnified.
Fig. 13. Leg of third pair, with gill.
Fig. 14. Leg of fourth pair, with gill.
Fig. 15. Leg of fifth jiair, with gill.

Fig. 1 6. Leg of penultimate pair, with giU and luminous organ.
Fig. 17. Gill of last pair, with rudiment of leg.

Fig. 18. Leg of penultimate pair, without gill and luminous organ ; more highly magnified.
Fig. 19. Rudimentary leg of last pair.
Fig. 20. Gill of second pair.
Fig. 21. Gill of third pair-.
Fig. 22. GiU of fourth pair.
Fig. 23. Gill of fifth pair.

Fig. 24. Gills of the two posterior pairs, on right side, in situ, from outer face.
Fig. 25. Spermatophores affixed to the genital openings of a female specimen.
Fig. 26. Extremity of tail, with caudal fan, from above.
Fig. 27. Inner plate of a male pleopod of first pair.
Fig. 28. Inner plate of a male pleopod of second pair.

Fig. 29. Copulatory appendage to first pleopod, isolated, and more highly magnified.
Fig. 30. Tip of copulatory appendage to second pleopod.

The Voyage of H. M. S." Challenger"

bci:

a. l: <J aj. •-- ' Ji:.

THYSANOESSA GREGARIA,r sp

; Anatomy).

PLATE XXllI.

(ZOOL. CHALL. EXP. PART XXXVII. 1885.) Oo.

PLATE XXIII.

Figs. 1-4. Thysanoessa macrura, G. 0. Sars.
Fig. 1. Female, from left side ; magnified about ten times.
Fig. 2. Anterior part of body, from above.
Fig. 3. Extremity of tail, with caudal fan, from above.
Fig. 4. Preaual spine.

Figs. 5-10. Nematoscelis megalops, G. 0. Sars.

Fig. 5. Adult female, from right side ; magnified about six times.
Fig. 6. Same, from above.
Fig. 7. Preanal spine.

Fig. 8. Anterior part of carapace, with the narrow rostral projection, froni left side.
Fig. 9. Same, from above.

Fig. 10. Right side of trunk, with gills in their natural position.

The Voyage of HM S.'CJiallenger"

W¥''i''^Vy

Figs 1-4, THYSANOESSA MACRURA, n sp
„ 5-10, NEMATOSCE LIS MEGALOPS . n gen i sp

. cHachta: StocHiolm.

PLATE XXIV.

Nematoscelis megalops, G. (J. Sars.
(Anatomy — continued. )

Ficf. 1. Anterior part of Ijody, with eyes, antennula3, anteunaj, anterior lip, and

mandibles, from below.
Fig. 2. Left antenuular peduncle, from above.
Fig. 3. Left antenna, from below.
Fig. 4. Anterior lip.
Fig. 5. Posterior lip.
Fig. 6. Mandible, with palp.

Fig. 7. Masticatory parts of mandibles, exhibiting the armature <>i the cutting edges.
Fig. 8. Mandibular palp.
Fig. 9. Maxilla of first pair.
Fig. 10. Maxilla of second pair.
Fig. 11. Maxilliped.

Fig. 12. Terminal joint of same ; more highly magnified.
Fis. 13. Leo' of first pair.

Fig. 14. Extremity of same ; more highly magnified.
Fig. 15. Outer part of a terminal spine ; highly magnified.
Fig. 16. Leg of second pair.

Fig. 17. Extremity of same ; more highly magnified.
Fig. IS. Leg of third pair.
Fig. 19. Leg of fourth pair.
Fig. 20. Leg of fifth pair.
Fig. 21. Leg of penultimate pair.

Fig. 22. Same, without the gill and luminous organ ; more highly magnified.
Fig. 23. Rudimentary leg of last pair.
Fig. 24. Gill of second pair.
Fig. 25. Gill of third pair.
Fig. 26. Gill of fourth pair.
Fig. 27. Gill of fifth pair.
Fig. 28. Gill of penultimate pair.
Fig. 29. Gill of last pair, with rudiment of leg.
Fig. 30. Extremity of tail, with caudal fan, from .ibove.

The Voyage of H. M S." Challenger"

G. O.Sars.ael

'^/i/IJ^-

NEMATOSCELIS M EGALOPS, n gen 4 sp

(Anatomy;

Lith-W Schlachta: Stockfi-.

PLATE XXY

^ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oo.

PLATE XXV.

Figs. 1-4. Nematoscelis microps, G. 0. Sars.
Fig. 1. Ovigerous female, from right side ; magnified about nine times.
Fig. 2. Anterior part of body, from above.
Fig. 3. Extremity of a leg of first pair.
Fig. 4. Extremity of tail, with caudal fan, from above.

Figs. 5-7. Nematoscelis tenella, G. 0. Sars.
Fig. 5. Female, from left side ; magnified about fourteen times.
Fig. 6. Anterior part of body, from above.
Fig. 7. Extremity of a leg of first pair.

Figs. 8-10. Nematoscelis 7'ostrata, G. 0. Sars.
Fig. 8. Female, from right side ; magnified about fourteen times.
Fig. 9. Anterior part of body, from above.
Fig. 10. Extremity of a leg of first pair.

•r.vsq.. nf-R, M, S; Challenger"

Sdiizopoda,?! 2X7:

G-. 0. Sars,de].

LithV?: ScMachta: .Stocfitcb:

Fig? 1_^, NEMATOSCELIS MICROPS.n sp Figs 5 _ 7, NEMATOSCELIS TENELLA.n Sp
Fig? 8_10, NEMATOSCELIS ROSTRATA, n sp

PLATE XXVl.

PLATE XXVI.

Stylocheiron carinahim, G. 0. Sars.

Fig. 1. Ovigerous female, from left side ; magnified about fourteen times.

Fig. 2. Left side of trunk, with the gills in situ, from outer face.

Fig. 3. Right antennular peduncle, from above.

Fig. 4. Right antenna, with scale and proximal part of flagellum, from below.

Fig. 5. Anterior lip and mandibles.

Fig. 6. Posterior lip.

Fig. 7. Masticatory parts of mandibles, exhibiting the armature of the cutting edges.

Fig. 8. Maxilla of first pair.

Fig. 9. Maxilla of second pair.

Fig. 10. Maxilliped.

Fig. 11. Extremity of same ; more highly magnified.

Fig. 12. Leg of third paii'.

Fig. 13. Leg of fourth pair.

Fig. 14. Leg of fifth pair.

Fig. 15. Leg of penultimate pair, with luminous organ.

Fig. 16. Gill of last pair, with rudiment of leg.

Fig. 17. Rudimentary leg of last pair, isolated, and more highly magnified.

Fig. 18. Extremity of tail, with caudal fan, from above.

Fig. 19. Adult male, from right side.

Fig. 20. The i'our posterior gills on right side of same, with the greatly developed

luminous organ at base of penultimate pair.
Fig. 21. Right male antennular peduncle, from above.
Fig. 22. Leg of second pair (exopod and gill omitted).
Fig. 23. Gill of penultimate pair in male, with the luminoixs organ.
Fig. 24. Last pair of gills, from below.
Fig. 25. Male pleopod of first pair.
Fig. 26. Inner plate of same ; more highly magnified.
Fig. 27. Inner plate of a male pleopod of second pair.

The Afoyage of H.M. S." Challenger"

yrhizopoda, PI.XaVi

<j. J. SarSidel.

lith."WSchlacr.

STYLOCHEIRON CARINATUM, n gen i sp.

PLATE XXYII.

(ZOOL. CHALL. EXP.^PART XXXVTI. — 1885.) — Oo.

PLATE XXVII.

Figs. 1-4. Stylocheiron suhmii, G. 0. Sars.
Fig. 1. Female, from right side ; magaified about eighteen times.
Fig. 2. Antennal scale.
Fig. 3. Extremity of a leg of second pair.
Fig. 4. Anterior part of body of a male specimen, from above.

Fig. 5. Stylocheiron longicorne, G. 0. Sars.
Fig. 5. Female, from right side ; magnified about eighteen times.

Figs. 6-10. Stylocheh'on elongatum, G. 0. Sars.
Fig. 6. Adult male, from right side ; magnified about twelve times.
Fig. 7. Antennal scale.
Fig. 8. Extremity of a leg of second pair.
Fig. 9. Inner plate of a male pleopod of first pair.
Fig. 10. Inner plate of a male pleopod of second pair.

Figs. 11-13. Stylocheiron ahbreviatum, G. 0. Sars.
Fig. 11. Female, from left side ; magnified about eighteen times.
Fig. 12. Right antenna, with scale and proximal part of flagellum, from below
Fig. 13. Extremity of a leg of second pair, forming a complete chela.

The "\foyage cf H. M S." Challenger"

Schizopoda.Pl IXTir

aaSars.del.

lithWSch]^;-

Fig? 1_4-, STYLOCHEIRON SUHMII,nsp Fig 5, STYLOCHEIRON LONGICORNE, n sp.

„ e_10, „ ELONGATUM,n sp ,,11.13, „ ABBREVIATUM, n sp

PLATE XXVIII.

Nyctiphanes cmstralis, G. 0. Sars.
(Early larval stages.)

Fif. 1. Larva in Metauauplius stage, from above; highly magnified.

Fig. 2. Same, from left side.

Fig. 3. Same, from below, more strongly magnified, exhibiting the budding limbs

behind the anterior lip.

Fig. 4. Larva in first Calyptopis stage, from right side ; highly magnified.

Fig. 5. Same, from above.

Fig. 6. Same, from below ; more strongly magnified.

Fio". 7. Anterior prominence of ocular segment, with the ocellus.

Fiff. 8. One of the antennulse.

Fio". 9. One of the antennae.

Fig. 10. Anterior lip and mandibles.

Fig. 11. Posterior lip.

Fio-. 12. Mandible.

Fig. 13. Cutting edge of left mandible.

Fig. 14. Cutting edge of right mandible.

Fig. 15. Appendicular plate of cutting edge.

Fig. 1 6. Maxilla of first pair.

Fig. 17. Maxilla of second pair.

Fig. 18. Maxilliped.

Fig. 19. Extremity of tail, from below.

Fig. 20. Larva in second Calyptopis stage, from left side ; highly magnified.

Fig. 21. One of the antennulse.

Fig. 22. Extremity of tail, from below.

Fig. 23. Larva in last Calyptopis stage, from right side ; highly magnified.

Fig. 24. Left antennulse, from above.

Fig. 25. Maxilla of first pair.

Fig. 26. Extremity of tail, with teLsou and uropoda, from below.

I'ijvmwvi,^'

G. 0. Sal

lithTfodhlachta: Siocaolir.

NYCTIPHANES AUSTRALIS, n sp.
( Early larval s'ages >

PLATE XXIX.

(ZOOL. CHALL. EXP.— PART XXXVII.— 1885.)— Oo.

PLATE XXIX.

Euphausia peUucida, Dana.

(Development.)

Fig. 1. Larva in second Calyptopis stage, from left side; highly magnified.

Fig. 2. Same, from above.

Fig. .3. Larva in last Calyptopis stage, from left side.

Fig. 4. Larva in first Furcilia stage, from right side.

Fig. 5. Same, from above.

Fig. 6. Larva in an intermediate Furcilia stage, from left side.

Fig. 7. Larva in last Furcilia stage, from right side.

Fig. 8. Anterior part of a larva in first Cyrtopia stage, from right side.

Fig. 9. Anterior part of a larva in a later Cyilopia stage, from left side.

Fig. 10. Young Euphausia, with all its limbs developed, from left side ; magnified about
twenty times.

The Ifeyage of H. M. S." Challenger"

Sduzopoda.Pl. UK.

f f f f

G. 0. Sars,del.

EUPHAUSIA PELLUCIDA, Dana.
( Development |

LithW Schlachtet StocKhohn.

PLATE XXX.

Eiiphausia pellucida, Dana.

(Development of the liml),s.)

Fig. 1. Left antcnnula of a larva ia second Calyptopis stage.

Fig. 2. Same part of a larva in last Calyptopis stage.

Fig. 3. Same part of a larva in last Furcilia stage.

Fig. 4. Same part of a larva in first Cyrtopia stage.

Fig. 5. Same part of a young Euphaiisia.

Fig. 6. Right antenna of a larva in last Furcilia stage, from below.

Fig. 7. Same part of a larva in first Cyrtopia stage.

Fig. 8. Same part of a young Eitphausia.

Fig. 9. Ocular segment, with left eye, of a larva in second Furcilia stage, from below.

Fig. 10. Mandible of a larva in first Furcilia stage.

Fig. 11. Same part of a larva in last Cyrtopia stage.

Fig. 12. Same part of a young Euphausia.

Fig. 13. Maxilla of first pair of a larva in last Calyptopis stage

Fig. 14. Same part of a larva in last Cyrptopia stage.

Fig. 15. Same part of a young Eiiphausia.

Fig. 16. Maxilla of second pair- of a larva in last Calyptopis stage

Fig. 17. Same part of a larva in last Cyrtopia stage.

Fig. 18. Same part of a young Eiiphausia.

Fig. 19. Maxilliped of a larva in last Calyptopis stage.

Fig. 20. Same part of a larva in first Cyrtopia stage.

Fig. 21. Same part of a larva in an intermediate Cyrtopia stage.

Fig. 22. Same part of a larva in last Cyrtopia stage.

Fig. 23. Leg of first pair of a larva in first i'urcUia stage.

Fig. 24. Same jjart of a larva in an immediately following Furcilia stage.

Fig. 25. Same part of a larva in second Furcilia stage.

Fig. 26. Same part of a larva in last Furcilia stage.

Fig. 27. Same part of a larva in last Cyrtopia stage.

Fig. 28. Left side of trunk, with gills, of a larva in last Furcilia stage.

Fig. 29. Same part of a larva in first Cyrtopia stage.

Fig. 30. Leg of fourth pair, with rudiment of gill of same larva.

Fig. 31. Left side of trunk, with gUls, of a larva in second Cyrtopia stage.

Fig. 32. Same part of a young Euphaui-ia.

Fig. 33. Pleopod of first pair of a larva in first Furcilia stage.

Fig. 34. Same part of a larva in second Furcilia stage.

Fig. 35. Same pai-t of a larva in last Furcilia stage.

Fig. 36. Extremity of tail of a larva in second Calyptopis stage, from below.

Fig. 37. Same part, with right uropod, of a larva in last Calyptopis stage.

Fig. 38. Same part of a larva in first Furcilia stage.

Fig. 39. Same part of a larva in second Furcilia stage.

Fig. 40. Same part of a larva in last FurciUa stage.

Fig. 41. Telson of a larva in first Cyrtopia stage.

Fig. 42. Extremity of tail, with telson and right uropod of a larva in last Cyrtopia stage.

The Ifoyage of H. M S.Tiallenger"

Schizopoda.Pl. TCL.

latnvv. icmacEiea.

(J. 0. Sars.del.

EUPHAUSIA PELLUCIDA, Dana
( Development oF [he limbs)

PLATE XXXI.

(ZOOL. CUALL. EXP. — PART XXXVII.— 1885.) Oo.

PLATE XXXI.

Figs. 1-22. Tliysanoiioda tricuspidata, Milne-Edwards.

(Development.)

ri;,^ 1. Larva in second Calyptopis stage, from left side ; highly magnified.

Fig. 2. Larva in last Calyptopis stage, from right side.

Fig. 3. Larva in first Furcilia stage, from left side.

Fig. 4. Same, from above.

Fig. 5. Larva in second Furcilia stage, from right side.

Fig. 6. Larva in second Cyrtopia stage, from left side.

Fig. 7. Eyes of a larva in last Calyptopis stage.

Fig. 8. Eye of a larva in second Furcilia stage.

Fig. 9. Same part of a larva in second Cyrtopia stage.

Fig. 10. Anterior part of body of a young Thi/sanopoda, from above.

Fig. 11. Same part, from left side.

Fig. 1 2. Tip of lateral protuberance of eye, with seven corneal lenses.

Fig. 13. JIanJible of a larva in last Calyptopis stage.

Fig. 14. Maxilla of first pair of same.

Fig. 15. Maxilla of second pair of same.

Fig. 16. Maxilliped of same.

Fig. 17. Extremity of tail of same larva, with telson and right uropod, from above.

Fig. 18. Telson of a larva in first Furcilia stage.

Fig. 19. Extremity of telson of a larva in second Furcilia stage.

Fig. 20. Same part of a larva in first Cyrtopia stage.

Fig. 21. Same part of a larva in last Cyrtojsia stage.

Fig. 22. Same part of a young Tliysanopoda.

Figs. 23-29. Nematoscelis rostrata, G. 0. Sars.

(Development.)

Fig. 23. Larva in Furcilia stage, from right side ; highly magnified.

Fig. 24. Larva in a subsequent Furcilia stage, from left side.

Fig. 25. Larva in Cyrtopia stage, from right side ; magnified about twenty-four times.

Fig. 26. Legs of first and second pairs of the larva represented in fig. 23, isolated, and more highly magnified.

Fig. 27. Telson of same larva, from above.

Fig. 28. Extremity of telson of the larva represented in fig. 24.

Fig. 29. Same part of a larva in Cyrtopia stage.

Figs. 30-31. Euphcmsia sp. (O-

(Larval stage.)

Fig. 30. Larva in first Furcilia stage, from right side ; magnified about eighteen times.
Fig. 31. Extremity of tail of same larva, with telson and riglit urnpod, friim above.

The Voyage of H. M. S.'Challen.^er"

5chizopod4,Pl. mi.

iji'X- 1 •' '-■' r-.fii.-i— '.^^

G.O.Sars,ael.

Fig? 1-22 THYSANOPODA TRICUSPIDATA, Edw
Figl 23-29, NEiriATOSCEUS R 0 STRATA, G 0 Sars F.g? 30-31, EUPHAUSlA?5p.

(Development)

PLATE XXXII.

Figs. 1-9. Petahyplithahmis armiger, Willemoes-Suhm.

Fig. 1. Adult male, from left side ; magnified about four times.

Fig. 2. Anterior part of liody, from above.

Fig. 3. One of the jjetaloid eyes.

Fig. 4. Eight antenna, from outer side.

Fig. 5. Gnathopod.

Fig. G. Maxilliped.

Fig. 7. A pleopod.

Fig. 8. Extremity of tail, with telson and right uropod, from above.

Fig. 9. Tij) of telson ; more highly magnified.

Figs. 10-20. Boreomysis sci/pho^JS, G. 0. Sars.

Fig. 10. Adult female, from left side ; very slightly magnified.

Fig. 11. Anterior division of body, together with first caudal segment, from left side;
somewhat more magnified. The free parts of the carapace have been
removed to show the segments oi the trunk with their liranchial folds ;
moreover, the gnathopods and legs are omitted, to show the seven
incubatory lamellfe issuing from their bases.

Fig. 12. Anterior division of body, together with the two anterior caudal segments,
from above. The dorsal body-wall, together with the viscera, have been
removed to show the nervous cord.

Fig. 13. Left eye, from outer face.

Fig. 14. jMandible, with palp.

Fig. 1 5. Maxilla of first pair.

Fig. 16. Maxilla of second pair.

Fig. 17. Maxilliped ; the terminal part of the exopodite is omitted.

Fig. 18. Gnathopod, with attached incubatory lamella.

Fig. 19. Outer part of a leg.

Fig. 20. Extremity of tail, with telson and left uropod, from above.

The VoyafSe of H. M. S." Challenger"

Schizopoda.Pl.imi

G.O.Sars.del

Fi<ss1-9 PETAL0PHTHALMU5 ARMIGER, Willcm Suhm S
" 10-20 BOREOMYSIS SCYPHOPS, GO Sars. ?

PLATE mm.

(ZOOL,

,. CH-UX. EXP. PART XXXVII. —1885.) — Oo.

PLATE XXXIII.

Figs. 1-6. Boveomysis obtusata, G. 0. Sars.

Fit;'. 1. Adult male, from left side; magnified about five times.

Fie;. 2. Carapace, with eyes, antennulse and antennte, from above.

Fig. 3. Frontal margin.

Fig. 4. Antennal scale.

Fig. 5. Outer part of a leg.

Fig. 6. Telson, from above.

Figs. 7-10. Boreomysis microps, G. O. Sars.

Fig. 7. Adult female, from above ; magnified about six times.

Fig. 8. Anterior part of body, with eyes, right antennular peduncle, and right antenna,
from above.

Fig-. 9. Telson. from above.

Fig. 10. Extremity of same ; more highly magnified.

Figs. 11-16. Amhlyops crozetii, Willemoes-Suhm MS.

Fig. 11. Adult male, from above ; magnified about five times.

Fig. 12. Same, from right side.

Fig. 13. Right antenna, with scale and proximal part of flagcllum, from lielow.

Fig. 14. Endopod of one of the anterior legs.

Fig. 15. Endopod of a leg of last pair.

Fig. 16. Telson, from above.

Figs. 17-18. Pseiidomma aiistrcde,^ G. (.). Sars.
Fig. 1 7. Anterior part of body of a male specimen, from aliove ; highly magnified.
Fig. 18. Same part, from right side.

' A)>i1ilyops by mistake on tlie ]ihiti'.

Echizopoda,?!. HXJH

Fi^M-e BOREOMYSIS 08TUSATA,n sp J Figl 11-16. AMBLYOPS CROZETII, Will.m Suhm M S. J
7-10. „ MICROPS n sp ? „ 17-18, „ AUSTRALIS, n sp. «

PLATE XXXIV.

Figs. 1-3. Pseudomma sarsii, Willemoes-Suhm MS.

Fig. 1. Adult male, from above ; magnified about ten times.
Fig. 2. Antennal scale.
Fig. 3. Telson, from above.

Figs. 4-27. Anchialus typicus, Kroyer.

Fig. 4. Adult ovigerous female, from right side ; magnified about twelve times.

Fig. 5. Same, from above.

Fig. 6. Adult male, from left side.

Fig. 7. Frontal part of carapace, with rostral projection, from above.

Fig. 8. Right anteunular peduncle of male, from below.

Fig. 9. Left antenna, with scale and proximal part of flagellum, from above.

Fig. 10. Anterior lip.

Fig. 11. Posterior lip.

Fig. 12. Mandible, with palp.

Fig. 13. Cutting edges of mandibles.

Fig. 14. Maxilla of first pair.

Fig. 15. Maxilla of second pair.

Fig. 16. Maxilliped.

Fig. 17. Male gnathopod.

Fig. 18. Leg of first pair of male.

Fig. 19. Leg of second pair.

Fig. 20. Outer part of a leg of last pair.

Fig. 21. Male sexual appendage.

Fig. 22. Anterior part of tail of female, viewed from the ventral face, to show the two

anterior pairs of caudal limbs and the epimera of first segment.

Fig. 23. Male pleopod of first pair.

Fig. 24. Male pleopod of fourth pair.

Fig. 25. Extremity of outer branch of same pleopod ; more highly magnified.

Fig. 26. Telson, from above.

Fig. 27. Right uropod, from above.

T'r.e Vovaee c:

.jer

Lrih.vr Siblndiiar SiocfeoiTrL

Fig- 1-3,PSEUD0MMA SARSH, Willem.Suhm, M.S.
4-27ANCHIALUSTrPICUS, Kroycr

PLATE XXXV.

(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) — Oo

PLATE XXXV.

Figs. 1-18. Anchialus angxistus, G. 0. Sars.

Fig. 1. Adult female, from right side ; magnified about fourteen times.

Fig. 2. Same, from above.

Fig. 3. Anterior part of carapace, from right side.

Fig. 4. Left antennular peduncle of male, from above.

Fig. 5. Left antenna, with scale and proximal part of flagellum, from above.

Fig. 6. Anterior lip.

Fig. 7. Posterior lip.

Fig. 8. Mandible, with palp.

Fig. 9. Maxilla of first pair. '

Fig. 10. Maxilla of second pair.

Fig. 11. Maxilliped (exopodite omitted).

Fig. 12. Male gnathopod (exopod omitted).

Fig. 13. Endopod of a leg.

Fig. 14. Male pleopod of second pair.

Fig. 15. Basal expansion of inner branch of same pleopod, more highly magnified.

Fig. 16. Male pleopod of fourth pair.

Fig. 17. Telson, from above.

Fig. 18. Eight uropod, from above.

Figs. 19, 20. Anchialus jmsillus, G. 0. Sars.

Fig. 19. Adult female, from right side ; highly magnified.

Fig. 20. Anterior part of body of another female specimen, obliquely from above.

Figs. 21-23. Mysidopsis incisa, G. 0. Sars.

Fig. 21. Adult female, from left side ; magnified about twenty times.

Fig. 22. Right antenna, with scale and proximal part of flagellum, from above.

Fig. 23. Extremity of tail, with telson and basal portion of right uropod, from above.

The Voyage of H. M S.'Cliallenger"

Schizopoda

G.O.Sars.del.

Figi1H8 ANCHIALUS ANGUSTUS n so. Fi^i 19-20, ANCHIALUS PUSILLUS,n sp
Fi^l 21-23 MYSIDOPSIS INCISA,n sp

Ltft.'WISchlaclrta: StocBiolin.

PLATE XXXYI.

Fig.

Fis;.

PLATE XXXVI.

Figs. 1-24. Siriella thompsonii, Milne-Edwards.

Adult male, from left side ; magnified about fourteen times.

Adult female, from right side.

Same, from above.

Left antennular peduncle of male, with the hispid lobe, from inner side.

Outer part of same peduncle, from below ; more highly magnified. The hairs
have been removed from the male appendage to show the double band gi^'ing
origin to the hairs.

Left antennae, with scale and proximal part of fiagellum, from below.

Anterior lip and mandibles, from below.
Fig. 8. Terminal joint of mandibular palp ; more highly magnified.
Fig. 9. Cutting edges of mandibles.
Fig. 10. Maxilla of first pair.
Fig. 11. Maxilla of second pair.
Fig. 12. Maxilliped.
Fig. 13. Gnathopod.

Fig. 14. One of the anterior legs ; somewhat less magnified.
Fig. 15. Outer part of same ; more highly magnified.
Fig. 16. Leg of last pair, with male sexual appendage.
Fig. 17. Male sexual appendage, isolated, and more highly magnified.
Fig. 18. Male pleopod of first pair.
Fig. 19. Male pleopod of second pair.
Fig. 20. Branchial lobe of a pleopod of first pair.
Fig. 21. Branchial lobe of a pleopod of second pair.
Fig. 22. Telson, from above.

Fig. 23. Extremity of same ; more highly magnified.
Fig. 24. Eight uropod, from above.

Figs. 25-28. Siriella gracilis, Dana.

Fig. 25. Adult female, from above ; magnified about twenty times.

Fig. 26. Right antenna, with scale and proximal part of fiagellum, from below.

Fig. 27. Extremity of tail, with telson and left uropod, from above.

Fig. 28. Tip of telson ; more highly magnified.

, Vi-raoa r'" "WT S "Challeii|er"

Sc>iiz(jpoda,Pl- IZZ'.I

■^

i&a'a

G. 0. Sars.del

Fi6l 1-24, SIRIELLA THOMPSONII, (Edw.)
25-28! „ GRACILIS, Dana.

PLATE XXXYII.

(ZOOL. CHALL. EXP. — PART XXSVII. — 1885.) — Oo.

PLATE XXXVII.

Figs. 1-20. Euchcetomera typica, G. 0. Sars.

Fio-. 1. Adult female, from alDove ; magnified about eleven times.

Fig. 2. Right antenuular. peduncle, from above.

Fig. 3. Left antenna, with scale and proximal part of flagellum, from above

Fig. 4. Anterior lip.

Fig. 5. Posterior lip.

Fig. 6. Mandible, with palp.

Fig. 7. Cutting edges of mandibles.

Fig. 8. Maxilla of first pair.

Fig. 9. Maxilla of second pair.

Fig. 10. Maxilliped.

Fig. 11. Gnathopod.

Fig. 12. Leg of first pair.

Fig. 13. Extremity of same ; more highly magnified.

Fig. 1 4. Outer part of a leg of last pair.

Fig. 15. Caudal limb of first pair of female.

Fig. 16. Caudal limb of last pair of female.

Fig. 17. One of the marginal setae of same ; highly magnified

Fig. 18. Male pleopod of first pair.

Fig. 19. Left uropod, from above.

Fig. 20. Telson, from above.

Figs. 21-24. Euchcetomera tenuis, G. 0. Sars.

Fig. 21. Female, from above ; magnified about fifteen times.

Fig. 22. Right antenna, with scale and proximal part of fiagellum, from above

Fig. 23. Endopod of a leg.

Fig. 24. Telson, from above.

The Voya^,e of H. M. S." Challenger"

rn.^--:

rVTF

-V

G.O.Sars,cLeI

Fig? 1-20, EUCH/tTOMERA TYPICA, n. gen A sp,
„ 21-2^! „ TENUIS, n.sp.

lath-V^Sdhlachta: Stodiholn.

PLATE XXXYIIL

PLATE XXXVIII.
Figs. 1-7. Heteromysis hermudensis, n. sp.

Fig. 1. Adult femalp, from right side ; magnified about eighteen times.

Fig. 2. Same, from above.

Fig. 3. Left antcnnular peduncle, from above.

Fig. 4. Antennal scale.

Fig. 5. Telson, from above.

Fig. 6. Young, in pupa-stage, extracted from the marsupial pouch, and viewed from right side; highly magnified.

Ficf. 7. Same, from below.

Figs. 8-14. Ecto- Parasites of Schizopoda.

Fio-. 8. Heteropltriixun appcndiculatus, n. gen. et sp., affixed to the dorsal face of a specimen of Euphausia
pellucid a; lateral view, a, female ; b, male.

Fig. 9. Notophryxiis lateralis, n. sp. («), affixed to base of penultimate giU of a specimen of Nematoscelis
inegalaps ; lateral view.

Fig. 10. Same parasite together with male (a), from below ; more highly magnified.

Fig. 11. Notophryxiis globularis, n. sp. (a), affixed to the posterior part of the dorsal face of carapace in a
specimen of Thysanoessa gregaria ; lateral view.

Fig. 12. Dajus siriellce, n. sp., female, with male (a) affixed, viewed from above; liighly magnified.

Fig. 13. Same (female and male), from below.

Fig. 14. Male, isolated and viewed from above ; more highly magnified.

Figs. 15-23. Endo-Para sites of Schizopoda.

Fi". 15. Echiiiorhynclius corrugatus, n. sp., lying within the perivisceral cavity of a specimen of Eiiphmisia
pdlueida ; lateral view.

Fig. 16. Same, isolated, and more highly magnified.

Fig. 17. Anterior extremity of same, with proboscis protruded.

Fig. 18. One of the hooks from the proboscis ; highly magnified.

Fi"-. 19. Distomum filiferuin, Leuckart, M.S., attached within the perivisceral cavity of a specimen of Nemato-
scelis megalops ; lateral view.

Fig. 20. A specimen of the parasite, together with the sac-like body, isolated, and viewed from below.

Fig. 21. Another specimen, with the Ijyssus thread exserted, from left side.

Fig. 22. Fragment of a byssus thread together with a number of fine adhesive fibres; highly magnified.

Fig. 23. A packet of adhesive fibres.

The Voya^,e of H. M. S;Clia.llengfer"

Schizopoda,?!. nZVI

^^-'- >-X,j.jj.; uj. .L--

C-. 0. Sars.del.

Lith."W StUadhtEt SiocHiolm.

ns? 1-7, HETEROMYSIS BERMUDEIMSIS, n. sp.
8-23, ECTO-A ENTO-PARASITES of Schizopoda

>K!^|i!F!ii:;^i;iffi

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Full text of "Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873-76 : under the command of Captain George S. Nares, R.N., F.R.S. and Captain Frank Turle Thomson, R.N."

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